Rendering in AliasStudio
Autodesk AliasStudio 2009
Rendering in AliasStudio
March 2008
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Contents
Rendering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Chapter 1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Workflow for rendering . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Rendering tools and menus . . . . . . . . . . . . . . . . . . . . . . . . 4
Render an image in a 3D scene . . . . . . . . . . . . . . . . . . . . . . . 5
Chapter 2
Understanding rendering textures . . . . . . . . . . . . . . . . . 7
Surface texture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Solid texture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Environment texture . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Texture Placement Objects . . . . . . . . . . . . . . . . . . . . . . . . 36
Projection texture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Cameras . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Camera editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Types of renderers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
What are rendering parameters? . . . . . . . . . . . . . . . . . . . . . 47
Preview rendering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Scene Description Language . . . . . . . . . . . . . . . . . . . . . . . 48
Chapter 3
How do I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
iii
Use the Multi-lister . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Apply shading to surfaces . . . . . . . . . . . . . . . . . . . . . . . . . 58
Change colors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Use the control window . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Add or edit textures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Apply surface textures . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Apply solid textures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Apply 3D environments . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Add and edit lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Add and edit cameras . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Add and edit image planes . . . . . . . . . . . . . . . . . . . . . . . . 107
Set rendering quality on a per-object basis . . . . . . . . . . . . . . . 115
Chapter 4
Troubleshoot . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Common rendering problems . . . . . . .
Common shadow image problems . . . .
Common aliasing problems . . . . . . . .
Common surfaces problems . . . . . . .
Common textures problems . . . . . . . .
Common motion blur problems . . . . . .
Common glows problems . . . . . . . . .
Common image planes problems . . . . .
Common miscellaneous object problems .
Overall image problems . . . . . . . . . .
Optimization . . . . . . . . . . . . . . . .
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. 121
. 123
. 125
. 125
. 126
. 127
. 130
. 132
. 132
. 135
. 136
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
iv | Contents
Rendering
Explains the basic rendering concepts used to define the look of a scene, which uses shaders,
textures, and lights; rendering images and animations.
1
2
Introduction
1
Introduces AliasStudio rendering features.
Rendering is the process of generating a two-dimensional image of a three-dimensional scene,
somewhat like taking a photograph with a camera, or filming with a motion picture camera.
Like photography, rendering requires that you determine a number of factors before you
actually render the image. You need to
■
Model the objects
■
Assign shaders and textures to objects
■
Optimize the scene
■
Light the scene
■
Set the size of the image to be produced
Rendering is an iterative and experimental process altering your environment to suit the
needs of your rendering image.
Workflow for rendering
Learn an overview on how rendering is done.
1 Define the appearance of the surroundings for your scene using the
environment and textures.
Define the surface appearance of objects in your scene using shaders and
textures.
Illuminate the objects in your scene using lights.
You should become familiar with the Multi-lister, the Control Window,
and the Color Editor. These are the tools you use to create and edit the
3
environment, shaders, textures, and lights. You can also use these tools
to help you create effects like smoke, fog, and halos around lights.
2 Set up the camera to render a particular view of your scene.
3 Preview render your scene to help you visualize how it will look in the
final render.
4 Define how individual objects and the overall scene will render using
rendering parameters.
5 Render your scene.
Rendering tools and menus
Describes the purpose and options of all tools and menu items.
Summary of the Rendering interface
A summary of the Render menus
Most rendering options are available from the Render menu. Use the following
table to access information on its choices.
Render >
For more information...
Render
Render > Render
Globals
Render > Globals
Direct render
Render > Direct render
Summary of other Rendering controls
Control
For more information...
Display Toggles > Hardware shade
WindowDisplay > Hardware Shade
File > Export > SDL
Scene Description Language on page 48
4 | Chapter 1 Introduction
Control
For more information...
Render > Create lights
Create a light on page 94 and Light types
defined on page 41
DisplayToggles > ObjectToggles > Lights
Create a light on page 94
Render > Multi-lister
Render > Multi-lister
Windows > Editors > Cameras
Windows > Editors > Cameras
Render > Editors > Light links
Render > Editors > Light links
Render > Editors > Render stats
Render > Editors > Render stats
Render an image in a 3D scene
Learn how to render a two-dimensional image in a three-dimensional scene.
To render a scene
See Environment texture on page 31, and Environment texture types on page
32.
1 Define the appearance of the surroundings for your scene using the
environment and textures.
See Assign or layer a shader on page 58, and Add or edit textures on page
69.
Define the surface appearance of objects in your scene using shaders and
textures.
Create a light on page 94
Illuminate the objects in your scene using lights.
See Use the Multi-lister on page 51, Use the control window on page 66,
and Change colors on page 63.
You should become familiar with the Multi-lister, the Control Window,
and the Color Editor. These are the tools you use to create and edit the
environment, shaders, textures, and lights.
Render an image in a 3D scene | 5
Add and edit cameras on page 103
2 Set up the camera to render a particular view of your scene.
Preview rendering on page 48
3 Preview render your scene to help you visualize how it will look in the
final render.
What are rendering parameters? on page 47
4 Define how individual objects and the overall scene will render using
rendering parameters.
Types of renderers on page 46
5 Render your scene.
What if...?
Rendering takes a long time and I want to improve it.
Optimization on page 136
Rendering can take a long time. There are, however, several ways you can
optimize your scene to minimize rendering times. It is a good idea to read the
Optimization section of this book before you begin the rendering process,
even before you begin modeling your scene.
What if...?
I have flaws in my rendering or it does not render at all.
Troubleshoot on page 121
If you encounter problems, read the Troubleshooting section of this book for
solutions to common problems.
6 | Chapter 1 Introduction
Understanding rendering
textures
2
Learn how to simulate various types of textures.
Textures are two-dimensional or three-dimensional patterns which you can assign, or map,
to certain parameters of environments, shaders, and lights. You can also assign textures to
certain parameters of other textures.
There are three basic types of textures:
■
Surface textures (two-dimensional textures)
■
Environment textures (three-dimensional textures)
■
Solid textures (three-dimensional textures)
The Texture Procedures window contains a list of all textures (Surface, Environments, and
Solid) and a list of all Texturable Values for the active environment/shader/texture/light.
7
Surface texture
Learn how to simulate various types of surface materials.
Surface textures are two-dimensional textures that simulate various types of
surface materials by using either an image file (File and Stencil textures) or a
computer graphic procedure (Bulge, Checker, Cloth, Curvature, Fractal, Grid,
Highlight, Mountain, Noise, Ramp, and Water textures).
There are thirteen different types of surface textures.
TIP Environment textures map to directions. Surface textures and solid textures
map to positions.
8 | Chapter 2 Understanding rendering textures
NOTE Do not map a surface texture to a shader’s Reflection parameter because
it will not produce realistic-looking reflections.
File texture
The File texture lets you use an image file as a surface texture. You can create
an image file using a paint package (for example, StudioPaint), using
AliasStudio’s integrated sketching tools (see the Sketching book), using a
scanner to scan in a photograph, or by rendering a scene.
Surface texture | 9
Bulge texture
The Bulge texture represents a grid of white squares which fade to grey toward
their edges. Use the Bulge texture as a bump or displacement map to create
surface bulges, as a transparency map to simulate windows that are dirty
around the edges, or as a color map to simulate tiles.
10 | Chapter 2 Understanding rendering textures
Checker texture
The Checker texture represents a checkerboard pattern.
You can modify the colors and size of the squares.
Cloth texture
The Cloth texture simulates fabric or other woven materials.
Surface texture | 11
When using cloth texture, remember the following:
■
Rendering will be faster if all three randomizing parameters (Randomness,
Width Spread, and Bright. Spread) are set to 0.
■
Very fine cloth textures may produce aliasing or moiré patterns, especially
when viewed from a distance. If this occurs, set the Randomness value to
a small non-zero value, or use Convert Solid Tex to convert the cloth
texture into an image file. Convert a solid texture to a File texture on page
83
■
If you apply the cloth texture as a bump or displacement map, set the U
Thread Color and V Thread Color to white, and the Gap Color to black,
and use the Intensity parameters (Amult and Aoffset) to control the
intensity of the bump/displacement effect. Decrease the Blurmult value
to provide greater definition in the bump/displacement effect. Generally,
the Amult and Blurmult values should be very low (less than 0.1).
12 | Chapter 2 Understanding rendering textures
Fractal texture
The Fractal texture represents a random function with a particular frequency
distribution (a fractal) and can be used to create many different types of effects.
Use the Fractal texture as a bump or displacement map to simulate rock or
mountains, or as a transparency map to simulate clouds or flames. The Fractal
texture has the same level of roughness at different levels of magnification
(that is, at different distances from the camera).
Surface texture | 13
Grid texture
The Grid texture represents a scalar grid pattern.
14 | Chapter 2 Understanding rendering textures
Mountain texture
The Mountain texture simulates rocky terrain using a two-dimensional fractal
pattern. Use the Mountain texture as both a color map and a bump or
displacement map (on a flat surface) to simulate snow capped mountains.
Surface texture | 15
If you do apply the Mountain texture as both a color map and a bump or
displacement map, note the following:
■
The texture calculates the color map based on the bump/displacement
map, so, for example, the location of snow is based on the surface’s
displacement.
■
The color parameters (Snow_color and Rock_color) of the Mountain texture
relate only to the color map, and have no effect on the bump/displacement
map. Similarly, all non-color parameters of the Mountain texture relate
only to the bump/displacement map, and have no effect on the color map.
■
The values of the Boundary parameter, the Snow Levels parameters, and
the Recursion Depth parameter (Level_max) of the bump/displacement
map will override those of the color map. For example, the Boundary value
of the bump/displacement map will control the raggedness of the snow/rock
boundary of the color map.
Noise texture
The Noise texture represents a random pattern of two colors. The Noise texture
will appear smoother the closer it is to the camera.
16 | Chapter 2 Understanding rendering textures
Ramp texture
The Ramp texture represents a gradation through a series of colors. The ramp
texture can be used to create many different types of effects (stripes, geometric
patterns, mottled surfaces).
Surface texture | 17
The default ramp texture is blue/red/black unless the texture is mapped to
certain single-channel parameters (for example, Reflectivity, Bump,
Displacement). In these cases the ramp is black/white/black.
18 | Chapter 2 Understanding rendering textures
Use a ramp texture:
■
as a two-dimensional environment background
■
as the source file for an environmental sphere texture to simulate a sky
and horizon
■
as the source file for a projection texture to simulate wood grain, marble,
or rock.
Very complex ramp textures may experience aliasing during an animation. If
this occurs, use Convert Solid Tex to convert the ramp texture into an image
file (see Convert a solid texture to a File texture on page 83).
Stencil texture
The Stencil texture is like File texture. It lets you use an image file as a surface
texture; however, it also lets you mask the image file to control how it covers
a surface. Use the Stencil texture to overlay different textures (and control
which parts of the textures are visible), or for label mapping.
Map a label to a shader on page 74
Surface texture | 19
Water texture
The Water texture simulates linear water waves, concentric water ripples (for
example, caused by an object falling into water), or a combination of waves
and ripples. Use the Water texture as a bump or displacement map to simulate
water, or as a color map to simulate light reflections or refractions from a
water surface.
The Water Texture Parameters include the Linear Wave Parameters which
control the appearance of linear water waves, and the Concentric Ripple
Parameters, which control the appearance of concentric water ripples.
20 | Chapter 2 Understanding rendering textures
Solid texture
Learn how to apply solid textures to surfaces.
Solid textures are three-dimensional patterns that simulate solid materials (for
example, wood or marble) by either using an image file or series of image files
(Projection and Volume textures) or using a computer graphic procedure
(Snow, sCloud, sFractal, sMarble, sRock, Leather, Granite, and sWood textures).
When you map a solid texture to a surface, the surface will appear to be carved
out of that material.
Environment textures map to directions. Surface textures and solid textures
map to positions.
Do not map a solid texture to a shader’s Reflection parameter because it will
not produce realistic-looking reflections.
Using solid textures
Typically, you use solid textures to make an object appear to be carved out of
a block of solid material (for example, wood or marble). Solid textures
determine the color of a surface based on the XYZ values of each point on the
surface. Solid textures are, therefore, not affected by the parameterization of
a surface, and will not distort (the way a surface texture will) when mapped
to a surface with uneven parameterization.
Projection texture
Use the projection texture to apply a 2D image to a 3D object by creating a
3D projection of the image.
The Projection texture converts a two-dimensional texture or image file into
a three-dimensional texture by projecting it in one or several directions. See
Render > Create texture projections > Planar Render > Create texture
projections > Concentric, Render > Create texture projections > Ball, Render
> Create texture projections > Triplanar, Render > Create texture projections
> Spherical, Render > Create texture projections > Cubic, Render > Create
texture projections > Cylindrical, and Render > Create texture projections >
Camera.
Snow texture
Use the Snow texture to give the appearance of snow, dirt, dust, or ash on
objects.
Solid texture | 21
To make snow appear on all objects in your scene, apply the Snow texture as
a transparency map on a white shader, and then layer this shader onto other
shaders. This way, the snow can have its own unique shading attributes.
Try combining a Fractal bump map with a Snow color map. The snow appears
only on the peaks and valleys of the bump-mapped surface. For best results,
set the Fractal bump map’s Amult and Blurmult values to a low number.
To simulate windswept snow, rotate the Snow texture by rotating the 3D
Placement Object about a horizontal line.
22 | Chapter 2 Understanding rendering textures
sCloud texture
The sCloud texture simulates clouds, but can also be used to create steam,
smoke, or fire effects.
When using sCloud texture, remember the following:
■
For best results, map the sCloud texture only to a sphere. The sphere can
be transformed in any way (for example, non-proportionally scaled), as
long as the actual base component is a sphere. You can combine several
spheres to create complex cloud arrangements. If you map the sCloud
texture to any other type of surface, the results are unpredictable.
■
The area surrounding the cloud is always transparent, regardless of the
type of mapping used.
■
You can also create smoke and fire effects using lights with fog and 2D
noise or with particles.
Solid texture | 23
sFractal texture
The sFractal texture represents a three dimensional random function with a
particular frequency distribution (a fractal) and can be used to create many
different types of effects.
24 | Chapter 2 Understanding rendering textures
sMarble texture
The sMarble texture simulates marble: a vein of material sandwiched between
layers of filler material, and diffusing into the filler material.
Solid texture | 25
sRock texture
26 | Chapter 2 Understanding rendering textures
The sRock texture simulates rock using a random, three dimensional
distribution of two different types of grain material.
Leather texture
The Leather texture simulates leather, but can also be used to simulate other
materials, including alligator skin, Styrofoam, and concrete, particularly when
used as a bump map.
Solid texture | 27
For many situations, an image file of real leather produces a good leather
simulation. However, it is often impossible to map a file texture to a surface
without distortions and discontinuity. Chord Length texture mapping may
eliminate distortions, but it requires some effort and does not always work.
In those cases, use the Leather texture.
The Leather texture uses a three-dimensional array of spheres to simulate
two-dimensional leather. This is unlike real leather because real leather is a
surface, not a solid. However, the Leather texture usually produces very realistic
results. One exception is if the surface is deformed during an animation,
because the surface will appear to move through the solid texture. In this case,
however, you can convert the solid texture to a File texture.
Convert a solid texture to a File texture on page 83
28 | Chapter 2 Understanding rendering textures
Granite texture
The Granite texture simulates granite using a random, three-dimensional array
of three different types of spheres suspended in a medium. The Granite texture
is like the Leather texture with three cell colors instead of one.
The Granite texture takes a long time to render. Convert it to a File texture
whenever possible.
Convert a solid texture to a File texture on page 83
Solid texture | 29
sWood texture
Use the sWood texture on surfaces to give the appearance of the object being
carved out of a block of wood.
The sWood texture simulates wood by projecting a two dimensional pattern.
This pattern consists of layers or concentric rings defined by veins and filler.
When you map the sWood texture to a surface, the surface appears to be
carved out of wood. If you map the sWood texture to several surfaces, they
appear to be carved from a single block of wood.
30 | Chapter 2 Understanding rendering textures
Volume texture
The Volume texture allows the Ball texture to use multiple image files.
You can use the Volume texture to specify any number of image files, although
32 is a reasonable maximum.
■
If you map a File texture to the Ball texture’s Image parameter, the Ball
texture can use only a single image file and the texture has a “pinch point”
or bad spot.
■
However, if you map a Volume texture to the Ball texture’s Image
parameter, the Ball texture selects the “best” image file (for the current
view) from the sequence of image files specified in the Volume texture.
The “best” image file for a view is the one whose bad spot is furthest away.
Environment texture
Learn how to simulate environmental reflections.
Environment overview
The environment defines the appearance of your scene’s surroundings. It can
be a simple colored background or a complex three-dimensional texture. The
environment also defines global lighting, shader glow, and fog for your scene.
All scenes must have an environment. By default, the environment is black
(giving the appearance of no environment). You can edit the default
environment and save the environment for use in other scenes, or you can
load an environment that you have previously saved.
Image Based Lighting (IBL)
Image based lighting offers additional realism through the use of high dynamic
range images (HDRI) as environment maps, and the treatment of that
environment map as a source of light, not just a reflection map.
Image based lighting takes reflection maps a step further into realistic rendering
by replacing the standard 24-bit reflection maps with High Dynamic Range
images. HDR images include more lighting data than a standard 24-bit image
does. This information can be used effectively in environments to capture the
bright and dark areas of the environment in not only reflections, but in the
specular highlights, diffuse component, and all other components of the
shader.
Environment texture | 31
HDRI images are environment maps, and may be spherical (latitude/longitude
maps) or cube environment maps stored as vertical cross images, which have
an aspect ratio of 3:4 (width to height).
HDR images can be created using Photoshop CS2, HDRIshop, or purchased;
some are available on the web, as well (try searching for “royalty-free HDR
images”).
The lighting produced by an HDR image, since it has a wide range, usually
needs to be “toned” to represent lighting that is suitable for the scene. This
toning is calculated near the end of the rendering process, and takes the full
scene into account, as well as actual lights that are used in the scene.
Environment texture
Environment textures simulate three-dimensional spaces. They can do this
by using a series of image files such as Ball, Cube, or Sphere textures; or by
using a computer graphic procedure such as Chrome or Sky texture. Typically,
you map an environment texture to one of the following:
■
the environment’s Color parameter as a background for your scene
■
a shader’s Reflection parameter to simulate environmental reflections
Environment textures map to directions. Surface textures and solid textures
map to positions.
Although you can map an environment texture to other parameters, they may
not give the results you expect. Do not map an environment texture to a
shader’s Bump or Displacement parameter:
■
An environment texture mapped to Bump produces unpredictable results.
■
An environment texture mapped to Displacement is ignored.
Environment texture types
There are several different types of environment textures: ball, chrome, cube,
sky, and sphere.
32 | Chapter 2 Understanding rendering textures
Ball Textures
The Ball texture uses an image (or series of images) of a highly reflective chrome
ball in an environment (real world or computer generated) to re-create that
environment. This is possible because the reflections in the chrome ball provide
a (nearly) 360 degree view of the environment.
A Ball texture background renders faster than a procedural texture background
or a background modeled with surfaces. You can therefore replace a complex
background with a Ball texture (by rendering an image of a chrome ball in
that environment) to reduce rendering times.
In order to use the Ball environment texture, you must map the texture’s
Image parameter with the image of a reflective chrome ball in the environment
you want to re-create. You should also map the environment’s Backdrop
parameter with the image of the environment without the chrome ball.
Environment texture | 33
Chrome texture
The Chrome texture simulates a showroom environment. The texture consists
of a ground plane and a sky plane (with fluorescent style light rectangles),
and provides a simple but effective environment to simulate reflections off
chrome surfaces.
34 | Chapter 2 Understanding rendering textures
Cube texture
The cube environment texture simulates an environment by mapping six
image files onto the inner surfaces of a cube or box. The size and shape of the
texture placement object determines the size and shape of the cube or box.
TIP To use a cube texture to simulate reflections from a real-world or CG
environment, from the center of the environment in all six directions either take
photographs of (real-world) or render (CG) the environment. Then map a cube
texture to a shader’s Reflection parameter, and assign the six images to the cube
texture. Scale and position the texture placement object so that it corresponds to
the dimensions of the original environment. Assign the shader to an object in your
scene and render (raycast). The object will appear to accurately reflect the original
environment.
One of the advantages of the cube environment texture is that you can blur
it without increasing rendering time.
Sky texture
Environment texture | 35
The Sky texture simulates a planetary environment viewed from the surface
of a planet.
NOTE If the eye point or view drops below the floor, the Sky texture swatch in
the Multi-lister will turn red as a warning. If you render the scene, the floor will
appear red. Make sure the eye point is always above the floor (the ground plane).
Sphere texture
The Sphere texture simulates an environment by mapping a texture or image
file directly onto the inner surface of an infinite sphere. The best way to create
a sphere environment is to use a ramp texture and paint objects onto it, being
sure to avoid the poles and edges.
Texture Placement Objects
Learn how to determine the origin position and direction of the texture in a
scene.
Every environment texture and solid texture in your scene has an associated
Texture Placement Object. The Texture Placement Object determines the
origin position and direction of the texture relative to the XYZ coordinate
system and to the objects in your scene. By transforming the Texture Placement
36 | Chapter 2 Understanding rendering textures
Object (using the standard Transform tools), you can control how the texture
maps to the environment or to the surfaces in your scene.
By default, the Texture Placement Object for all textures is invisible. You can
display a texture’s Texture Placement Object in the modeling windows by
clicking the texture placement icon in the bottom right corner of the texture’s
Multi-lister swatch.
The Texture Placement Object for a solid texture appears in the modeling
windows as a cube with one cross-hatched face, and an arrow pointing in one
direction. By default, the Texture Placement Object for any solid texture is
positioned at the origin with its arrow pointing in the positive Y direction.
The Texture Placement Object for a Projection texture is different for each
Projection type.
Projection texture on page 39
The Texture Placement Object for an environment texture appears in the
modeling windows as an icon with an arrow pointing in one direction. The
type of icon is different for each type of environment texture. By default, the
Texture Placement Object for any environment texture is positioned at the
origin with its arrow pointing in either the positive Y direction (for Y-up
scenes) or the positive Z direction (for Z-up scenes). For example, the Texture
Placement Object for the Sky texture consists of a line between the sun and
the origin, allowing you to easily see the sun’s azimuth and elevation.
Texture Placement Objects | 37
The Texture Placement Object also appears in the SBD window as a separate
transformation node beneath the texture node.
38 | Chapter 2 Understanding rendering textures
The name of the Texture Placement Object is listed in the texture’s Control
Window with the 3D Placement parameters.
To associate a texture placement object with surfaces, use Render > Place
projection.
Projection texture
Learn how to create a three-dimensional texture by projecting it in one or
several directions.
The Projection texture converts a two-dimensional texture or image file into
a three-dimensional texture by projecting it in one or several directions. This
is the same method used by the sMarble and sWood textures, so you can, for
example, use scanned or painted image files with the Projection texture to
create a variety of three-dimensional wood or marble textures. The Projection
texture is also useful for converting a surface texture or image file to a solid
texture to avoid texture distortion due to non-uniform surface
parameterization.
Projection texture | 39
Note the following when using the Projection texture:
■
When using the Projection texture with textures that use fractal noise (for
example, Fractal, sFractal, sCloud, sMarble), keep the Recursion Depth
Level_min and Level_max values as low as possible to minimize rendering
time. See Recursion Depth in Render > Multi-lister.
■
You can use the Surface Placement and Label Mapping parameters of a
texture that is mapped to a Projection texture to adjust the projection
effect.
■
You can create a Projection Object before creating the actual texture in
the Multi-lister, by using the Texture Projection Object tools.
Lights
Learn how to use lights in your scene.
Lights illuminate objects. If your scene contains no lights, then it will render
entirely black (unless, for example, you are using shaders with incandescence).
You can also use lights to create special optical effects (for example, halos,
lens flares, or fog).
40 | Chapter 2 Understanding rendering textures
Light types defined
There are seven different types of lights. There is also a tool for creating default
lighting for a scene.
Point light
Point lights are like incandescent light bulbs—they cast light in all directions.
See Render > Create Lights > Point.
Spot light
Spot lights cast light in one direction only, emanating from a point in a cone.
See Render > Create Lights > Spot.
Directional light
Directional lights are directional source lights that have color, intensity, and
direction, but no obvious source in the scene. See Render > Create Lights >
Directional.
Ambient light
Lights | 41
Ambient lights are similar to point lights except that only a portion of the
illumination emanates from the point. The remainder of the illumination
comes from all directions and lights everything uniformly. See Render > Create
Lights > Ambient.
Area light
Area lights are two-dimensional rectangular light sources. See Render > Create
Lights > Area.
Volume light
Volume lights define a closed volume in which objects will be illuminated,
and nothing outside the volume is directly illuminated by the light. See Render
> Create Lights > Volume.
Linear light
Linear lights are one dimensional line-like lights similar to fluorescent tubes).
See Render > Create Lights > Linear.
Default lighting
42 | Chapter 2 Understanding rendering textures
The Create defaults tool sets the default lighting for a scene. When you select
Render > Create Lights > Create defaults, an ambient light and a directional
light are automatically created. Their orientation and position are pre-defined
and their values are based on each light’s default options.
Cameras
Use cameras to view a scene.
Cameras are objects that you use to view a scene. A modeling window
represents the view from a camera. This view is used to create an image of
your scene during rendering.
A camera represents a particular view of your scene. By changing the position
and orientation of a camera, and the properties of the camera’s lens and film,
you can control the camera’s view.
A modeling window represents the view of a particular camera. Each modeling
window has an associated camera, but each camera does not necessarily need
to have an associated modeling window.
Cameras | 43
There are two types of cameras: orthographic and perspective. The view from
an orthographic camera does not include the effect of perspective. That is, an
object will appear the same size no matter how far it is from the camera. The
view from a perspective camera includes this effect; an object will appear larger
when it is close to the camera, and smaller when it is far from the camera.
A single scene may contain several cameras. For example, by default a scene
contains four cameras corresponding to the four modeling windows: top,
front, right, and perspective (camera). You can render the view from one or
several of the cameras in a scene.
In some cases a modeling window may not represent the exact view of a
camera. For example, if the aspect ratio of the film back does not match the
aspect ratio of the camera’s modeling window, then the window will only
44 | Chapter 2 Understanding rendering textures
show a portion of the camera’s view (see Film Back Properties in Windows >
Editors > Cameras). Another example is the magnify window which represents
a magnified view of a modeling window.
A perspective camera appears in the SBD window as a group of nodes
representing the camera’s position (eye point), view (look at point), and up
point. You can also display perspective cameras in the orthographic modeling
windows as a green icon. Orthographic cameras do not appear in the SBD
window unless the camera has an image plane.
Camera editor
Learn how to edit cameras and image planes.
The Camera Editor is the primary interface that you use to edit cameras and
image planes.
Camera Editor parameters behave similarly to Control Window parameters
(see Use the control window on page 66).
The Camera Editor contains parameters which control the properties of cameras
and image planes. The title bar of the Camera Editor contains a keyframe
button which lets you set a keyframe for a parameter, and a model pick button
which lets you select the modeling window associated with the current camera
in the Camera Editor.
Image planes
An image plane is an image that you can attach to a camera’s view. This image
appears in the camera’s modeling window and in images rendered from that
camera (either in front of or behind the scene). Any camera can have one or
several image planes. For example, you could use an image plane as a visual
reference when building a model or as a background for your scene when
rendering.
Camera editor | 45
NOTE In AliasStudio for Windows there are two types of image planes: animation
image planes and canvas planes. See the Painting book for more information on
canvas planes.
An image plane appears in the SBD window beneath the camera’s eye node.
This it is not a hierarchical grouping, however. Any transformations you make
above the eye node do not affect the image plane. If you add an image plane
to an orthographic camera, the orthographic camera appears in the SBD
window with the image plane beneath its eye node.
Types of renderers
Learn about raycast, raytrace, and hidden line renderer process types.
In addition to hardware shading, which happens in real time on your computer
display, there are three single processor types of renderer (raycast, raytrace,
46 | Chapter 2 Understanding rendering textures
and hidden line) and two multi-processor types of renderer (powercast, and
powertrace). You can render a scene using any of these renderers either
interactively within AliasStudio, or to the AliasStudio renderers from a UNIX
command line. You can also test render a scene at a lower resolution.
When you render a scene, a stream of data is sent to the renderer.
The results of rendering will be created in the appropriate directories of your
local Studio environment, regardless of which renderer you use.
Raycasting
Raycasting produces smooth shaded renderings that include shadows.
Raycasting is faster than raytracing, but does not produce reflections or
refraction. (You can simulate reflections using reflection maps and simulate
refraction using linear transparency.) Raycasting is often required for long
animations to keep the total rendering time within a reasonable limit.
Raytracing
Raytracing produces smooth shaded renderings that include reflections,
refraction, and shadows.
Hidden Line
Hidden line rendering produces a cartoon or sketch style rendering. Outlines
for the objects are rendered in the shader color, and the objects are filled with
white.
Powercasting and Powertracing
The PowerCaster and PowerTracer are multi-processor versions of the RayCaster
and RayTracer. By using the PowerCaster or PowerTracer you can render a
scene using a select number of processors of a multi-processor computer.
What are rendering parameters?
Rendering parameters control how a scene will render. There are two types of
rendering parameters: global rendering parameters and object rendering
parameters. Global rendering parameters are contained in the Render Globals
window, and control how the overall scene will render. Object rendering
parameters are contained in the Render Stats window, and control how
individual objects will render.
What are rendering parameters? | 47
Preview rendering
Learn how to preview the appearance of the scene.
If you are presenting an initial concept design, you may want your presentation
to have a stylish sketched look. You can create this type of image by creating
a sketch and a simple model, then using Render > Place projection on a
roughed-in model, and using either WindowDisplay > Hardware Shade or
Render > Direct render.
Before you do a final render, you will want to preview the appearance of
objects, shaders, textures, and lights using one of the preview renderers.
Preview rendering is typically faster (and lower quality) than final rendering.
Use Render > Direct render for preview software renderings.
Direct render
Direct render is a convenient way to launch and monitor one or more renders
while working within AliasStudio.
Direct render opens a new window on top of the active window, and renders
that window’s view using the selected renderer.
Select one of the following five Studio renderers
■
Raycaster
■
Raytracer
■
Hidden Line
■
Powercaster
■
Powertracer
depending on what option or options you have available with your software.
Scene Description Language
Learn how SDL files can be used by renderers.
SDL is the Scene Description Language that is used by AliasStudio renderers.
An SDL file is a binary file that can be converted, using the command line
utility bsdl, to a text file that contains all the information necessary to render
a scene, including models, shaders, lights, and animation. Because they can
48 | Chapter 2 Understanding rendering textures
be converted to text files, you can edit an SDL file using a text editor and SDL
commands. Usually, however, you will not need to directly edit SDL files.
Instead, the interactive modeling program will stream data to the renderer.
There are, however, some cases where you may want to edit an SDL file:
■
for absolute, mathematical control over scene elements such as models,
animation paths, and shaders
■
to modify a generated SDL file manually, or with another program
■
to create new procedural effects using the general programming features
of SDL.
By applying basic programming constructs to scene descriptions you can create
useful and spectacular effects that would be tedious or impossible to create
with the interactive modeler alone. You can also augment the dynamics and
particle systems of the interactive modeler with the flexibility of the SDL
programming language.
Once you have an SDL file describing a scene, you can then render it using
one of the stand-alone renderers (see Use a command line rendering program
on page 120). See the Scene Description Language online documentation for
more information.
Scene Description Language | 49
50
How do I
3
How to perform rendering tasks in AliasStudio.
Use the Multi-lister
Learn how to use the Multi-lister.
The Multi-lister is the primary interface that you use to create, edit, manage
and display shaders, textures, lights, and the environment. You also use the
Multi-lister to access the Control Window and the Color Editor.
Open the Multi-lister
How to open the Multi-lister to create, edit, manage, and display shaders,
textures, lights, and the environment.
To open the Multi-lister
■
Select Windows > Multi-lister to display the Multi-lister menu. The menu
item you use to open the Multi-lister will determine the type of swatches
listed in the Multi-lister.
You can display:
■
a specific type of swatch (select Shaders, Lights, or Glows)
51
■
selected (picked) lights or shaders that are assigned to active (picked)
objects (select Picked)
■
all swatches: the environment, and all shaders, lights, and textures
(select List all).
See Change the Multi-lister displayfound below.
After you open the Multi-lister, you can change the type of swatches listed.
If there are no shaders or lights in memory, the Multi-lister lists two
swatches: the environment and the default shader.
You can position the Multi-lister window anywhere on the screen, resize
it or stow it, like any other AliasStudio window.
NOTE The Multi-lister may seem to take a long time to open. There may be
an NFS problem: Use the file reference to determine if there are any invalid
file paths that access NFS mounted file systems. Repair any incorrect NFS
referenced files before opening the Multi-lister.
Change the Multi-lister display
How to change the type, size, or style of swatches listed in the Multi-lister.
For example, if you have many shaders, texture, and lights, you may want to
only display lights, or to display small swatches, or low resolution swatches,
to speed up the Multi-lister display.
To change the type of swatches listed in the Multi-lister
See List menu in Render > Multi-lister.
■
From the List menu in the Multi-lister, select one of the following: All,
Shaders, Lights, Glows, Picked, Linked Lights, or Non-excl Lights.
To change the size or style of swatches in the Multi-lister
■
Click one of the following icons in the Multi-lister title bar:
52 | Chapter 3 How do I
To change the resolution of a swatch in the Multi-lister
1 Click the swatch to make it active.
2 Click-drag the white triangle on the right side of the swatch (up to increase
resolution, down to decrease resolution).
NOTE The Multi-lister may not display very low resolution swatches. In these
cases, increase the swatch resolution.
Select an environment, shader, texture, or light
How to select an environment, shader, texture, or light to edit your parameters.
NOTE You must select an environment, shader, texture, or light in order to use
the Control Window to edit its parameters, or to use many of the Multi-lister menu
tools. You can select one or many shaders, texture, lights, or the environment.
To select a shader, light, texture, or the environment
■
Click on the swatch in the Multi-lister. The selected swatch is highlighted
in white.
If either the Control Window or Color Editor is open, its display updates
with the parameters for the selected swatch in the Multi-lister.
Use the Multi-lister | 53
If the selected environment, shader, light, or texture has a texture mapped
to one of its parameters, the corresponding texture swatch in the Multi-lister
is also selected and partially highlighted in white.
To select several shaders, lights, textures, or the environment
■
Shift-click on the swatches in the Multi-lister. The first selected swatch is
highlighted in white, and all other selected swatches are highlighted in
gray.
Create a shader or light
How to create and copy new shaders and lights.
When you start a new scene, there is only the environment and one shader
(the DefaultShader) defined (and assigned to all objects). You can create a new
shader (based on the DefaultShader) or light, or copy a shader or light that
you have customized.
Shader#1 and Light#1 are not used explicitly as names; the first shader or light
with a given name is implicitly numbered 1.
54 | Chapter 3 How do I
TIP By default, shaders and lights are named sequentially as you create them:
DefaultShader, Shader, Shader#2, and so on, and Light, Light#2, and so on. To
avoid confusion, however, you should name all your shaders and lights as you
create them. If you let the system assign default names and later combine two or
more files, all shaders and lights will be renumbered to avoid duplicate names. It
may then become difficult to distinguish shaders and lights by name.
To create a new shader
See New Shader in Render > Multi-lister.
■
In the Multi-lister, select Edit > New Shader. A new shader swatch appears
in the Multi-lister. The new shader has the same properties as the
DefaultShader.
Create a light on page 94
To create a new light using the Multi-lister
See New Light in Render > Multi-lister.
■
In the Multi-lister, select Edit > New Light. A new point light swatch appears
in the Multi-lister and in the modeling windows at 0,0,0.
To copy a shader or light
1 In the Multi-lister, click on the swatch of the shader or light you want
to copy.
See Copy in Render > Multi-lister.
2 In the Multi-lister, select Edit > Copy. A new shader or light swatch
appears in the Multi-lister. The new shader/light has the same properties
as the original shader/light.
Edit an environment, shader, texture, or light
How to edit an environment, shader, texture, or light.
To edit a shader, texture, light, or the environment
Use the control window on page 66
1 Double-click the environment, shader, texture, or light swatch in the
Multi-lister to open the Control Window.
Use the Multi-lister | 55
2 Edit the parameters to customize the environment, shader, texture, or
light.
To change the name of an environment, shader, texture, or light
1 Double-click the name of the environment, shader, texture, or light in
the swatch in the Multi-lister.
2 Type in the new name and press Enter.
You cannot give an environment, shader, texture, or light the same name
as any other shader, texture, or light, or object in your scene. This is
because the SDL file uses the same naming convention for shaders,
textures, lights, and objects. If you attempt to enter a name that is already
in use, the system will display a warning that the shader, texture, light,
or environment will be renamed. The system then assigns a number after
the name to make it unique.
If you want your shaders to have the same names as the objects to which
they are assigned, you can assign object names with all lowercase letters
and shader names with mixed case letters. This creates enough of a
difference that each name is considered unique.
To delete a shader, texture, or light
1 In the Multi-lister, click on the swatch of the shader, texture, or light you
want to delete.
See Active in Render > Multi-lister.
2 In the Multi-lister, select Delete > Active.
Save and load an environment, shader, texture, or light
How to create a library of environments, shaders, textures, and lights.
You can save a shader, texture, light, or environment to a file that is
independent from your scene’s wire file to create a library. You can then load
a saved shader, texture, light, or environment into any other scene.
To save an environment, shader, texture, or light
1 Click on the swatch in the Multi-lister.
See Save as, Save in Render > Multi-lister.
56 | Chapter 3 How do I
2 From the File menu in the Multi-lister, select either Save or Save as.
■
If you select Save, the shader, texture, light, or environment will be
saved under its current name.
■
If you specify a different file name, the
environment/shader/texture/light name will still be saved within the
file. When you load the shader, texture, light, or environment back
into AliasStudio, it will then have its original name (providing the
name is not already in use).
■
If you select Save as, you can specify a different file name to save the
shader, texture, light, or environment under.
NOTE You can create a new default shader by editing the default shader
and then saving it with the name DefaultShader in the default shader
directory. If you edit the default shader, but don’t save it, the edited
shader will be used as the default shader for the remainder of your session
only.
To load an environment, shader, texture, or light
See File menu in Render > Multi-lister.
1 From the File menu in the Multi-lister, select either Shader Browse, Texture
Browse, Light Browse, or Environment Browse to open the File Requestor.
The shader, texture, light, or environment will have its original name
(providing the name is not already in use), no matter what the file name
is.
2 Use the File Requestor to select the shader, texture, light, or environment
you want to load, and click either Load Shader, Load Texture, Load Light,
or Load Environment.
NOTE To load more than one shader, texture, or light, click the Show List
button in the File Requestor if necessary, and Shift-click on the
shaders/textures/lights that you want to load. (If you are using the Windows
File Browser, Ctrl-click on each file, or Shift-click to select a range of files.)
NOTE There is always only one environment loaded in a scene. If you load
another environment, it will replace the original environment.
Use the Multi-lister | 57
Apply shading to surfaces
How to create and assign shaders.
Assign or layer a shader
How to assign a shader and layer shaders to a surface.
To assign a shader to a surface
1 Pick the surface(s) in a modeling window.
2 Pick the shader in the Multi-lister.
See Assign Shader in Render > Multi-lister.
3 Select Shading > Assign Shader in the Multi-lister.
To layer shaders onto a surface
1 Pick the surface(s) in the modeling window.
2 Pick the shader in the Multi-lister that you want to layer another shader
on top of.
See Assign Shader in Render > Multi-lister.
3 Select Shading > Assign Shader in the Multi-lister.
4 Pick the shader in the Multi-lister that you want to be layered on top of
the first shader.
See Layer Shaders in Render > Multi-lister.
5 Select Shading > Layer Shaders in the Multi-lister.
What is required for shaders to work
Shaders determine what surfaces look like (for example, color, reflectivity,
roughness). Once you create a shader, you can assign it to one or more surfaces.
You can also layer more than one shader onto a single surface.
In order for a surface to have the properties of a shader, you must assign the
shader to the surface. You can assign a single shader to several different
surfaces. You can also layer several shaders onto a single surface. By default,
all surfaces have the DefaultShader assigned to them.
58 | Chapter 3 How do I
Apply reflection to a shader
How to map a texture directly to a BLINN or PHONG shader’s Reflection
parameter to simulate reflections during raycasting or raytracing.
To reflection map a shader
Normally the renderer only calculates reflections during raytracing. However,
you can map a texture directly to a BLINN or PHONG shader’s Reflection
parameter to simulate reflections during raycasting or raytracing. For example,
you can use an environment texture as a reflection map to simulate
environmental reflections. Another use of reflection maps is to produce
identical reflections on several surfaces. Although you can use any texture as
a reflection map, environment textures give the best results.
NOTE By default, reflection mapping only works during raycasting. To use
reflection maps during raytracing, you must set the shader’s Use Refl. Map
parameter ON (see Use Refl. Map in Render > Multi-lister).
TIP You can also simulate reflections on a LAMBERT shader by mapping an image
file or texture to the shader’s Color or Incandescence parameter.
1 Double-click the shader swatch in the Multi-lister to open the Control
Window.
2 Click the Map button (to the right of the Reflection parameter) to open
the Texture Procedures window.
3 In the Texture Procedures window, click the button of the texture you
want to use.
The texture swatch appears in the Multi-lister, and the texture appears
on the shader swatch.
4 If you want to use the reflection map during raytracing, set the shader’s
Use Refl. Map parameter ON (see Use Refl. Map in Render > Multi-lister).
Move a shader from or to the shader library on the Visualization
control panel
Drag the shader with the middle mouse button.
Apply shading to surfaces | 59
Assign a shader to a surface using the Visualization control panel
To assign a shader to a surface
1 Pick the object(s) in a modeling window.
2 Pick the shader in the Multi-lister, the SBD, or the Visualization control
panel.
3 Select the Assign Current Shader
icon.
To change the assigned shader
1 Pick the shaded object.
2 Pick another shader.
3 Click the Assign Current Shader icon.
To display shaders on surfaces
Select the Toggle Shade icon, a tool located at the bottom of the Visualization
panel. The scene is shaded.
Modify attributes of shaders
Watch the movie.
Modify a shader’s color and intensity
1 Pick a surface on the shaded model to modify its color.
60 | Chapter 3 How do I
2 Push the bar under the Resident Shaders section in the Visualization
control panelup to reveal the full menu of shaders. The most commonly
used shader parameters are shown in this section of the panel.
3 In the Shader Parameters options, click on the rectangular color swatch
located under RGB Color and next to the color slider.
This opens the color palette where you can choose a different color for
the shader.
4 Change the color by clicking on the color wheel. You can modify the
color’s intensity in the HSV triangle.
5 Close the window when you’ve got a new color selected.
6 Click the Assign Current Shader
picked surface.
icon. The color updates on the
Apply shading to surfaces | 61
Layer shaders onto a surface
To create a layered shader
1 Pick the objects in the modeling window.
2 Click the Create Layered Shader i
con in the Visualization control
panel. A black shader highlighted in red appears in the Resident Shaders
section.
3 Double-click the black shader highlighted in red. The Layered Shader
window appears.
4 Select the shader in Resident Shaders you want to layer another shader
on top of in Resident shaders. Click once to highlight the selected shader
in red.
5 Click Add on the Layered Shader window. The Shader’s name is listed in
the window, and the black shader now displays your first shader choice.
6 Pick the shader in Resident Shaders that you want layered on top of the
first shader. Click once to highlight the selected shader in red.
7 Click Add in the Layered Shader window. The Shader’s name is listed in
the window and the shader displays a preview of the layers you have
chosen.
62 | Chapter 3 How do I
8 Click the Assign Current Shader
to your picked object.
9 Click the Toggle Shade
icon to assign the layered shader
icon to shade the object.
Change colors
How to use the editor to change the colors of environments, shaders, textures,
and lights.
Open the Color Editor
How to open the Color Editor from either the Control Window or from the
Multi-lister.
To open the Color Editor from the Control Window
Click the color field of the parameter that you want to edit.
The Color Editor opens. Notice that the parameter’s color field in the Control
Window is highlighted with a white border, and the Color Editor’s title bar
contains the shader name and parameter name.
Change colors | 63
Once the Color Editor is open, you can select any swatch in the Multi-lister
or any parameter’s color field in the Control Window, and the Color Editor
will automatically update.
To open the Color Editor from the Multi-lister
Select Edit > Color.
Select and edit colors
How to set the current color.
You can set the current color by selecting a color from the color palettes,
editing the current color using the range fields, or by grabbing a color from
anywhere on the screen.
To edit a color using RGB values
Adjust the RGB sliders or enter the RGB values in the RGB numeric fields.
To edit a color using HSV values
Adjust the HSV sliders or enter the HSV values in the HSV numeric fields.
64 | Chapter 3 How do I
To select a color using the color palette
1 Click the Pick button (unless it is already selected).
2 Click a square in the color palette to select that color.
To select a color using the color blending palette
Click in the color blending palette to select that color. If you click-drag within
the palette, the current color will update interactively.
To grab a color from the screen
1 Click the Grab button. The mouse pointer becomes a medicine dropper.
2 Move the medicine dropper over the part of the screen you want to grab
a color from, and click the mouse button. The grabbed color becomes
the current color.
You cannot use this method to grab a color from a Show Pix (that is, a pix file
that you are viewing using File > Show image ) because the image’s window
will close when you click on it. Use the following method, instead.
To grab a color from a Show Pix image
1 Click the Grab button. The mouse pointer becomes a medicine dropper.
2 Move the medicine dropper somewhere outside of the Show Pix image
window, and click-hold the mouse button.
3 Move the medicine dropper over the part of the Show Pix/wrl image you
want to grab a color from, and release the mouse button.
The grabbed color becomes the current color.
To undo a change you have made
Click the Undo button.
The active parameter’s color is reset to the setting the parameter had when
you first opened the Color Editor (or if the Color Editor was already open,
when you first selected the environment, shader, texture, or light, or first
selected the parameter).
Change colors | 65
Customize the color palettes
How to customize the color palette and the color blending palette to make it
easy to select certain colors.
To add a color to the color palette
1 Click Drop (unless it is already selected).
2 Set the current color (for example, using the range fields).
3 Click any square of the color palette to place the current color in it.
To add a color to the color blending palette
1 Set the current color (for example, using the range fields).
2 Click a corner square of the color blending palette.
Use the control window
How to use to edit shaders, textures, lights, and the environment.
Open the Control Window
How to open the Control Window for a shader, texture, light, or for the
environment.
■
Double-click the environment, shader, texture, or light swatch in the
Multi-lister
or
■
Click on the environment, shader, texture, or light swatch in the
Multi-lister, and select Edit > Edit in the Multi-lister.
Copy parameter settings
How to copy parameter settings from one environment, shader, texture, or
light to another.
1 Open the Control Window for the shader you want to copy parameter
settings from (for example, Shader).
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2 Hold the Shift key and click the shader swatch for the shader you want
to copy parameter settings to (for example, Shader#2).
3 In the Control Window, hold the Shift key and click on the names of the
parameters you want to copy (for example, Color and Transparency). The
parameter names become highlighted.
See Copy Parameters in Render > Multi-lister.
4 Select Edit > Copy Parameters in the Multi-lister. The parameter settings
are copied (from Shader to Shader#2).
5 Shift-click the parameter names again to deselect them.
Animate parameters
How to animate an environment, shader, texture, or light parameter by creating
key frames for the parameter.
Use the control window | 67
To create a keyframe for a parameter
1 Hold the Shift key and click the name of the parameter you want to
animate (for example, Color). The parameter name becomes highlighted.
2 Go to the frame of your animation that you want to create a parameter
keyframe for.
3 Adjust the parameter setting or value for that frame.
4 Use the right mouse button to click the Key button in the title bar of the
Control Window. A white parallelogram or diamond icon appears in the
Control Window beside the parameter name and in the Multi-lister
swatch. These animation icons indicate that a parameter is animated.
5 Shift-click the parameter name again to deselect it.
To play back an animated environment, shader, texture, or light in
the Multi-lister
Click-hold the animation icon in the lower left corner of the environment,
shader, texture, or light swatch in the Multi-lister.
68 | Chapter 3 How do I
Add or edit textures
How to add, assign, or map textures to parameters of your environment, shader
and lights.
Open a texture procedures window
To open the Texture Procedures window
■
In the Control Window, click on a parameter’s Map button.
Set the texture placement object
To position an environment texture or a solid texture
1 Click the texture placement icon in the bottom right corner of the
texture’s Multi-lister swatch. The Texture Placement Object appears in
the modeling window.
2 Select the Texture Placement Object in a modeling window.
3 Use the Transform tools (Move, Rotate, Scale, Non-p Scale) to change the
Texture Placement Object’s size, position, and orientation relative to the
ground plane or the surfaces in your scene that the texture is mapped to.
The effect of the transformations is updated interactively in the
Multi-lister.
4 Click the texture placement icon in the bottom right corner of the
texture’s Multi-lister swatch. The Texture Placement Object disappears
from the modeling windows.
Add or edit textures | 69
To toggle the visibility of all displayed Texture Placement Objects
■
Select DisplayToggles > Object Toggles > Textures. This only toggles the
visibility of Texture Placement Objects which you have previously displayed
by clicking the Texture Placement Icon in the Multi-lister.
To open the Toggle Textures Options box
■
Select DisplayToggles > Object Toggles > Textures r to display the Toggle
Textures Options box.
Map a texture
How to assign a texture to any environment, shader, texture, or light parameter
that has a Map button.
To map a texture to a parameter
See Color fields and Map buttons in Render > Multi-lister.
1 In the Control Window, click the Map button beside the parameter you
want to apply a texture to. The Texture Procedures window appears.
See Texturable Values in Render > Multi-lister.
If you want to apply the same texture to more than one parameter, click
on Texturable Values to open its section, and then Shift-click on the
parameters you want to apply a texture to.
2 In either the Surface, Environments, or Solid section of the Texture
Procedures window, click on the texture you want to map to the
parameter.
If the texture is inverted when you map it to a surface, use Surface Edit
> Reverse Surface UV to reverse the direction of the surface’s UV
parameterization.
The File, Stencil, Ball, Cube, Sphere, Projection, and Volume textures are
entirely black until you specify an image file or a series of image files.
Use surface textures
Uses for surface textures
■
The File and Stencil textures are used to specify an image file.
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■
The Curvature texture is used by the Surf curvature and Surf curv params
tools.
■
The Highlight texture is used by the Highlight and Highlight params tools.
Reduce surface texture distortion
Surface textures are mapped to a surface’s parametric space. That is, the XY
values of the texture are mapped to the UV parameters of the surface. If the
surface’s UV parameterization is non-uniform (that is, the U and V
isoparametric curves are not uniformly spaced), then the texture will appear
distorted. This often occurs when mapping a surface texture to a curved surface.
The greater the surface curvature, the less uniform the parameterization, and
the greater the texture distortion.
If a surface texture appears distorted on a surface, do one of the following:
■
Make sure that your surface is evenly parameterized. You can use Surface
Edit > Rebuild surface to re-create it with uniform parameterization.
See Chord Length in Render > Multi-lister.
■
Use chord length mapping by setting Chord Length ON.
See Projection Texture Parameters in Render > Multi-lister.
■
Use the surface texture as a source texture for a Projection solid texture.
■
Turn off U and V wrap if you don’t need them (this applies to any texture
placement with Ucoverage or Vcoverage less than 1.0).
Label mapping
Label mapping is a technique of applying an image file onto a surface (for
example, a label on a shampoo bottle) and masking parts of the image file so
that it covers only a portion of the surface. The Stencil surface texture is used
for both mapping and masking.
Add or edit textures | 71
Label masking
A mask controls the transparency of a Stencil texture and limits the area on
a surface where the texture will be visible. There are two types of masks: file
masks and chroma key masks.
File masking
File masking uses a texture or image file to specify which areas of the Stencil
texture are transparent. Where the Mask file is white, the Image file will be
visible on the surface. Where the Mask file is black, the shader color will be
visible on the surface. Where the Mask file is grey, both the Image file and
the shader color will be partially visible.
If the Image file has four channels (RGBA), then you can use the same file for
both the Image file and the Mask file. The RGB information will be used for
the image portion of the stencil and the A (alpha) will be used for the mask
portion of the stencil. If, however, the Image file has only three channels
(RGB), then you must create a separate Mask file.
You can create a Mask file by converting the Image file to black and white
using a paint program. Although you can use a color image file as a Mask (for
example, you could use the same file for both the Image and Mask), the level
of transparency of the mask will vary through the range of colors.
Chroma key masking
Chroma key masking does not require a mask file. Instead, you set the Stencil
texture’s HSV Color Key parameters so that a certain color, or a certain range
of colors, are either visible or invisible.
Chroma key masking has no effect if an image file is mapped to Mask. Make
sure there is no Mask file assigned to the Stencil texture (type a space in the
Mask field) if you want to use chroma key masking.
Position surface textures
By default, a texture mapped to a surface covers the entire surface. You can
mask the texture so that it is only visible in certain areas of the surface. You
can also scale or position the texture so that it covers only a certain area of
the surface.
See Surface Placement and Label Mapping in Render > Multi-lister.
Two sets of parameters control the positioning of the texture: the Surface
Placement parameters and the Label Mapping parameters. If you adjust these
72 | Chapter 3 How do I
parameters in the texture’s Control Window, the shader swatch in the
Multi-lister will update to reflect any changes you make. Therefore, by editing
these parameters directly and using the Multi-lister as a preview, you can
roughly position a texture on a surface. There is an easier method of
positioning a texture on a surface: 2D mapping.
Each surface texture swatch in the Multi-lister has a small icon in its bottom
right corner. Clicking on this icon opens the 2D texture mapping window. It
is also possible to use 2D mapping and Hardware Shading simultaneously, so
you can see how the map is positioned on the surface.
2D mapping
The 2D mapping technique uses the Texture Placement window to display
and position a texture. The horizontal and vertical dimensions of this window
(S and T) represent the two parametric dimensions of the active surface (U
and V). A texture mapped to the active surface will therefore be displayed in
the Texture Placement window relative to the surface. The buttons at the
bottom of the Texture Placement window allow you to interactively edit the
position and orientation of the texture relative to the surface.
Apply surface textures
How to simulate various types of surface materials by using either an image
file or a computer graphic procedure.
Surface textures are two-dimensional textures that simulate various types of
surface materials by using either an image file (File and Stencil textures) or a
computer graphic procedure (Bulge, Checker, Cloth, Curvature, Fractal, Grid,
Highlight, Mountain, Noise, Ramp, and Water textures).
Apply surface textures | 73
TIP Environment textures map to directions. Surface textures and solid textures
map to positions.
NOTE Do not map a surface texture to a shader’s Reflection parameter because
it will not produce realistic-looking reflections.
Map a label to a shader
1 In the shader’s Control Window, click the Map button to the right of the
Color parameter. The Texture Procedures window appears.
If you are planning to mask the label, continue with step 2.
If you do not need to mask the label, you can skip to step 4.
2 In the Texture Procedures window, click the Stencil button.
The Texture Procedures window automatically closes, a Stencil texture
swatch appears in the Multi-lister, and the Control Window displays the
texture’s parameters.
3 In the Stencil texture’s Control Window, click the Map button beside the
Image field. The Texture Procedures window appears.
4 In the Texture Procedures window, click the File button. The Texture
Procedures window automatically closes, a File texture swatch appears
in the Multi-lister, and the Control Window displays the texture’s
parameters.
5 In the Control Window, type the name of the image file you want to use
as the label in the Image field, or click the Browse button and select the
image file using the File Requestor.
The image file is now mapped onto the shader, and appears on the shader
swatch in the Multi-lister. By default, the image file covers the entire
shader. However, you can limit the area it covers by masking the label
or positioning it on the shader.
74 | Chapter 3 How do I
Mask a label using an image file mask
1 In the Stencil texture Control Window, click the Map button beside the
Mask parameter. The Texture Procedures window appears.
2 In the Texture Procedures window, click the File button. The Texture
Procedures window automatically closes, a File texture swatch appears
in the Multi-lister, and the Control Window displays the texture’s
parameters.
3 In the Control Window, type the name of the image file you want to use
as the mask in the Mask field, or click the Browse button and select the
mask file using the File Requestor.
The Mask is now mapped onto the shader, and the Image file no longer
covers the entire shader swatch in the Multi-lister. The Mask file is in the
same location as the Image file.
To control the overall transparency of the Stencil texture, adjust the
Rgbmult value in the Mask file’s Control Window.
To control the softness of the mask, adjust the Bluroffset value in the
Mask file’s Control Window. Small values (around 0.01) are most useful.
Mask a label using chroma key masking
1 In the Stencil texture Control Window, click on HSV Color Key to display
the HSV Color Key parameters.
2 Set Key Masking ON.
3 Click the color field beside Color Key to open the Color Editor.
4 Click the Grab button in the Color Editor. The mouse pointer becomes
an eye dropper.
5 Move the eye dropper over the Multi-lister, and click the left mouse button
on the background color of the Image texture. All areas of the Image
texture that have this color are now transparent (masked) and the shader
color is visible in these areas.
To mask a range of colors, adjust the Hue Range, Sat Range, Val Range,
and Threshold settings.
Apply surface textures | 75
To invert the mask, set Positive Key ON. Only the color (or range of colors)
specified in the HSV Color Key parameters are visible, instead of masked.
When you are finished masking the label, click the arrow in the bottom right
corner of the shader swatch to hide the Stencil texture and the Image file (and
the Mask file if there is one).
To preview the label map and mask, use Quick render. You may want to open
the Global Quick Rendering Parameters window and increase the Shading
Frequency value to better visualize the label map and mask. However, if you
have to increase the Shading Frequency value to 10, it may be faster to do a
full render.
To position the texture on a surface, see Positioning Surface Textures below.
Use 3D mapping to position a texture on a surface
1 Make sure that the texture mapped shader is assigned to the appropriate
surface, and that this surface is the only active object in the modeling
window.
2 Open the texture’s Control Window, and open the Surface Placement
and Label Mapping sections.
3 Click the 3D mapping icon in the bottom right corner of the texture
swatch in the Multi-lister.
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The modeling window displays the texture directly on the wire frame of
the surface.
4 If necessary, increase the patch precision of the surface to better visualize
the texture. Patch precision represents the number of curves (visual
isoparametric curves) that are displayed to represent each patch on a
surface. On most surfaces, the default patch precision of 2 is too low for
3D mapping. Increasing the patch precision, however, will also increase
the screen refresh time.
Select Object Edit > Patch precision and enter a number between 2 and
30. The number of visual isoparametric curves per patch increases, making
the texture pattern more visible.
Apply surface textures | 77
5 You may want to use Hardware Shade display mode to better visualize
the texture. Select DisplayToggles > Hardware Shade. The surface is
displayed in shaded mode.
6 Adjust the Surface Placement and Label Mapping parameters until the
texture is correctly positioned on the surface.
The Label Mapping parameters control the position and orientation of
the texture relative to the surface (see Label Mapping in Render >
Multi-lister).
The Surface Placement parameters control the position and orientation
of the texture pattern relative to the texture (Surface Placement in Render
> Multi-lister).
7 Click the 3D mapping icon in the bottom right corner of the texture
swatch in the Multi-lister. The modeling window no longer displays the
texture directly on the wire frame of the surface.
8 If you turned on the Shade display mode in step 5, select DisplayToggles
> Hardware Shade to turn it off.
9 If you increased the patch precision of the surface in step 4, reset the
patch precision of the surface to its default value (2). Select Object Edit
> Patch precision and enter 2.
Use 2D mapping to position a texture on a surface
1 Make sure that the texture mapped shader is assigned to the appropriate
surface, and that this surface is the only active object in the modeling
window.
2 Click the 2D mapping icon in the bottom right corner of the texture
swatch in the Multi-lister.
See Texture placement window in Render > Multi-lister.
The Texture Placement window opens and displays the texture relative
to the active surface.
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See Transform menu in Render > Multi-lister.
3 Use the Transform tools in the Texture Placement window to position
and orient the texture relative to the surface. The texture’s Surface
Placement and Label Mapping parameters are automatically updated
when you use the Transform tools.
4 Close the Texture Placement window, either by clicking the 2D mapping
icon in the texture swatch in the Multi-lister, or by clicking the close box
in the top left corner of the Texture Placement window.
Texture Placement window
To open the Texture Placement window
1 Select the texture swatch in the Multi-lister.
Apply surface textures | 79
2 Click the 2D mapping icon in the texture swatch.
Link a texture image file to an object
1 Click the Add button in the Per Object Images list. A blank line is added
to the list.
An “S” (supertexture) icon appears in the File texture’s Multi-lister swatch
and in the shader’s Multi-lister swatch.
2 Either:
■
double-click in the Object field and type the name of the object, or
■
click on the object in the modeling window so that it is the only active
object, and then click the Set button in the Per Object Images list.
The object name appears in the Object list.
80 | Chapter 3 How do I
3 Either:
■
double click in the Image field (beside the object name in the Object
list) and type the image file name, or
■
click the Browse button beside the Image field and select the image
file using the File Requestor. The image file name appears in the Image
list beside the object name in the Object list.
The image file will be applied only to that object.
Apply solid textures
Learn how to apply solid textures.
Typically, you use solid textures to make an object appear to be carved out of
a block of solid material (for example, wood or marble). Solid textures
determine the color of a surface based on the XYZ values of each point on the
surface. Solid textures are, therefore, not affected by the parameterization of
a surface, and will not distort (the way a surface texture will) when mapped
to a surface with uneven parameterization.
Create cloud effects using solid textures
To create a cloud using the sCloud texture, create a new shader and set the
shader parameters as follows:
■
Set Shading Model to LAMBERT
■
Set Color to white (or grey for smoke)
■
Set the Refractive Index value to 1
Apply solid textures | 81
■
Map Transparency with an sCloud texture.
Transparency is a 3-channel (RGB) mapping. As a result, the sCloud texture
requires more settings to work properly as a transparency map. Set the sCloud
parameters as follows:
■
Set Invert ON
■
Set Color1 and Color2 to white
■
Adjust the Transp_range value to make the cloud more dense.
Apply the shader to a sphere.
Create flame effects using solid textures
To create flames using the sCloud texture, create a new shader and set the
shader parameters as follows:
■
Set Shading Model to LIGHTSOURCE
■
Set Color to black
■
Set the Refractive Index value to 1
■
Set Transparency to its maximum setting (white)
■
Set the Glow value to 0.5
■
Map Incandescence with an sCloud texture.
Set the sCloud parameters as follows:
■
Set Color1 to pure green and Color2 to pure red
■
Set the Transp_range value to 0.3
■
Set the Center_thresh value to -0.5
■
Set the Amplitude value to 2
■
Set Rgbmult to a Value of 2.
Apply the shader to a sphere or an elongated (non-proportionately scaled)
sphere. Non-proportionately scale the sCloud texture’s Object Placement
Object to create a more vertical looking flame.
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Create smoke effects using solid textures
To simulate smoke, use the Create flame effects using solid textures example
to create a shader, set the shader Color to black, and apply the shader to an
elongated sphere positioned above the flame sphere. Animate the
transformation icon slowly upwards.
To create an explosion effect, animate the sphere being scaled up.
To create a roaring fire, animate the transformation icon for the texture,
moving it upward at a constant rate.
Create glow effects using solid textures
To create glows using the sCloud texture, create a new shader as described in
Create flame effects using solid textures. Set the sCloud texture’s Amplitude
value to 0, assign the shader to a sphere, and put the object that you want to
glow inside the sphere.
Convert a solid texture to a File texture
One of the disadvantages of using a solid texture is apparent during animation.
When you animate a surface that is mapped with a solid texture, the surface
will appear to flow through the solid material. One method of solving this
problem is to convert the solid texture into a File texture.
To convert a solid texture into a File texture
1 Pick the surfaces you want to create a new shader for.
2 In the Multi-lister, pick the shader for the selected surfaces.
3 Select Edit > Convert Solid Tex in the Multi-lister. A dialog box appears.
Apply solid textures | 83
The default value for Pix Size is 256 pixels square. Image files are created
and sized so that the Pix Size corresponds to the longest dimension of
the largest selected surface. If more than one surface is selected, the other
image files are proportionally smaller. The valid range is 8 to 1024 pixels.
TIP Larger image files require more memory to render, and depending on
the render specifications, may not noticeably improve render quality. Anti
Aliasing is recommended in most circumstances, but Convert Solid Tex will
take four times longer than if Anti Aliasing is OFF.
NOTE Convert Solid Tex places the newly generated image files in a
sub-directory (that has the same name as the shader being converted) in the
pix directory of the current project.
4 Click OK. Information is displayed in the information line.
The progress bar at the far right indicates the status of the current pix
creation.
Re-parameterize a polyset
1 Pick the polyset(s) you want to re-parameterize.
2 Create a new shader and click the Map button beside any parameter in
the shader’s Control Window. (The specific parameter you map the
Projection texture to is unimportant.)
3 Select the Projection texture from the Texture Procedures window.
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4 Select a Projection type in the Projection texture’s Control Window.
5 Position and orient the Projection texture’s Texture Projection Object in
the modeling windows.
6 In the Projection texture’s Control Window, set Clean Seams and
Normalize Seams ON, and click the Apply Mapping button beside Project
to UV. The polyset is now re-parameterized.
7 Create a new shader (or use an existing shader) that uses a surface texture
only (no environment textures or solid textures), and assign it to the
polyset. The surface texture now appears projected onto the polyset.
If, after rendering, you are not satisfied with the position and orientation
of the texture on the polyset, you can re-parameterize the polyset by
re-positioning and re-orienting the Projection texture’s Texture Projection
Object, and then clicking the Apply Mapping button again.
Apply the camera projection method to solid textures
1 Set Projection to CAMERA. The Projection Texture Parameters window
expands, listing all cameras that have an image plane. (You can only use
the CAMERA projection method for cameras that have an image plane.)
2 Click the Projective Camera toggle box for the camera you want to create
a Projection texture for.
3 Click the Create button. A Stencil texture representing the image plane
is automatically mapped to Source Texture.
Source Texture The two-dimensional texture or image file projected to create
a three-dimensional texture.
If you map Source Texture with a File texture, make sure that the File texture’s
Filter parameter is set to either NONE or BLEND. Higher order filters
(QUADRATIC, QUARTIC, and GAUSSIAN) give unpredictable projections.
Although you can use an environment texture or solid texture as a Source
Texture, the results are unpredictable.
Apply solid textures | 85
Create a smear map to a solid texture
1 Select the surfaces you want to create a smear map for.
2 In the Multi-lister, double-click the Projection texture to open its Control
Window.
3 In the Projection texture Control Window, click the Convert to Smear
button under the Effects section.
4 A dialog box appears.
The default Pix Size is 256 pixels square. Image files are created and sized
so that the Pix Size corresponds to the longest dimension of the largest
selected surface. If more than one surface is selected, the other image files
are proportionally smaller. The valid range is 8 to 1024 pixels.
TIP Larger image files require more memory to render and, depending on
the render specifications, may not noticeably improve render quality. Anti
Aliasing is recommended in most circumstances, but Convert to Smear takes
four times longer than if Anti Aliasing is OFF.
NOTE Convert to Smear places the newly generated image files in a
sub-directory (that has the same name as the shader being converted) in the
pix directory of the current project.
5 Click OK. Information is displayed in the information line.
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The progress bar at the far right indicates the status of the current pix
creation.
6 When the Convert to Smear operation is complete:
■
the Projection texture is replaced by its Source Texture,
■
a File texture is mapped to this texture’s Smear Map parameter, and
■
the File texture’s Per Object Images list contains a separate image file
for each selected surface.
Each selected surface now has its own Smear Map which has all of the
same properties as the original Projection texture.
Notes
■
Because the Convert to Smear operation destroys the Projection texture,
you may want to save the texture (or copy its shader) before using Convert
to Smear.
■
If you press Esc during the Convert to Smear operation, the files created
up to that point will be correct but will not necessarily be assigned. Even
if you delete the shader used by Convert to Smear, the image files still exist
in a directory with the name of the original shader in the current pix
directory. If you do a second Convert to Smear operation using the same
shader and objects, the previously created files are overwritten without
warning.
■
You can use Convert to Smear for spline type surfaces.
■
Any image files created are referenced on the Per Object Images list of the
new file texture. Each surface gets its own image file for every Projection
texture converted. The File texture created has no default Image file, only
per object files, therefore the shader swatch does not display the file texture.
To display the texture on the shader swatch, copy any image file name
from the Per Object Images list to the default Image field (click in the
Object list to highlight the image file name, then click in the default Image
field with the middle mouse button to paste).
Convert to Smear has the following limitations:
■
If Wrap is OFF for the Projection texture, Convert to Smear does not convert
the texture properly.
Apply solid textures | 87
■
The Source Texture can only have certain Surface Placement and Label
Mapping settings:
■
Uoffset, Voffset, Utranslate, and Vtranslate can be set to anything
■
Rotate should be set to 0
■
Ucoverage and Vcoverage should be set to 1
■
Urepeat and Vrepeat must have the same value; the Rgbmult on the
Smear Map must be scaled by the repeat value. For example, if Urepeat
and Vrepeat are both 5, then set the Rgbmult “value” on the Smear
Map to 5.
■
If the Source Texture has an image file or texture mapped to Rgboffset,
Rgbmult, or Overlay, then you must map a copy of the Smear Map (the
File texture created by Convert to Smear) to that image file or texture.
■
Bump and displacement maps may show artifacts.
Projection tools
There are two ways to create a Projection texture: using the Multi-lister or
using the Projection tools.
■
To create a Projection texture in the Multi-lister, you first create a shader,
map a Projection texture to the shader, and then position the Projection
texture using its Texture Projection Object.
■
If you create a Texture Projection Object in the modeling window, the
Projection tools create a corresponding shader and Projection texture in
the Multi-lister.
There are eight different types of Projection tools, representing the eight
different types of projections. See Projection Texture Parameters in Render >
Multi-lister for a description of each projection type.
Apply a planar projection on to a solid texture
1 Click or click-drag in a modeling window to place the pivot point of the
new Texture Projection Object.
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A new shader appears in the Multi-lister, having a Projection texture
mapped to its Color.
Tips
■
The projection objects are moved by their pivot points. When they are
created, the Planar and Tri-planar projections are not centered on their
pivot points.
■
When you are using the Camera projection, it may be helpful to pick the
objects you want to texture first, then use the Look at tool in the Cameras
palette before creating the projection object.
Apply 3D environments
How the environment defines the appearance of your scene’s surroundings.
Apply 3D environments | 89
NOTE If you are raytracing your scene, any reflective surfaces will accurately reflect
the environment.
To use image-based lighting
1 Open the Environment shader.
2 Instead of mapping an environment texture to the Background color
choose a high dynamic range image reflection map to use in the
Image-Based Lighting section. Browse to the HDR image, and choose it.
3 To evaluate the mapping, ensure that Use Environment (this option used
to be called Refl. Background) is turned ON in each shader that you want
to use an image-based lighting environment.
4 Turn on Use Environment in WindowDisplay > Hardware Shade.
As you can see from the following image, all of the shading parameters
of each shader affect the appearance of the image-based lighting.
5 Note that there are two Image-Based Lighting (IBL) environments provided
in the shader library, and that most of the shaders in the library have
been adjusted to work well with IBL.
After you have loaded the HDR image, you will probably need to adjust
the tone of it; since HDR images cover a wide range of lighting conditions,
the default selection may not be the look you want. Open the next section
of the Environment shader, the Tone Mapping section.
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Adjust the Exposure, Saturation, and Gamma sliders to adjust the color,
brightness, and tonal range of the HDR image.
Image-based lighting can be used with both Hardware Shade and software
Render modes.
Create a 3D environment
1 Double-click the environment swatch in the Multi-lister to open the
Control Window.
See Control Window in Render > Multi-lister.
2 In the Control Window, click the Map button (to the right of the Color
parameter) to open the Texture Procedures window.
Apply 3D environments | 91
Open a texture procedures window on page 69
3 In the Texture Procedures window, click Environments to open the
environment texture section.
See Environment parameters in Render > Multi-lister.
4 Click the button of the environment texture you want to use.
An environment texture swatch appears in the Multi-lister, the
environment texture is displayed on the environment swatch, and the
Control Window updates to display the environment texture parameters.
5 Customize the environment texture by editing the parameters in the
Control Window.
Create a Ball environment
To create an image of a chrome ball, first place a highly reflective chrome ball
(sphere) in the environment (real world or computer generated) that you want
to re-create. Place the ball at the exact location (in the original environment)
where you want your model to appear (in the re-created environment), and
take note of the ball’s distance from any floor/walls/ceiling or large objects.
Photograph (or render) the ball using a telephoto lens, and take note of the
camera’s elevation (the angle between the camera’s view and the environment’s
ground plane), and the camera’s inclination (the angle between the camera’s
view and the environment’s YZ plane).
The photo essentially contains a compressed sample of the entire environment,
except for the area directly behind the ball. The highest resolution is in the
direction of the camera, so the image provides the best data compression for
that point of view.
A Ball texture that uses a single photograph of a ball has two limitations: the
missing area directly behind the ball, and the decreasing resolution toward
the edges of the ball. You can overcome these limitations by taking a series
of photographs of the ball (up to a maximum of 32). The photographs must
be taken on the horizontal plane of the ball (that is, not above or below the
ball), at a constant distance from the ball, and at equal intervals around the
ball. The Ball texture will automatically select the best image for any particular
view (that is, no missing area and maximum resolution). Name the image files
<filename>.1 through <filename>.n, where the files represent a sequence
going clockwise around the ball when viewed from above.
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Remove the ball from the environment, and photograph (or render) the
environment again using the same camera position, elevation, and inclination,
but a wider angle lens (for example, 24mm to 50mm).
The Ball texture can best re-create environments that have no objects in their
center (that is, near the chrome ball). For example, rooms and interiors should
not contain furniture, and outdoor scenes should not have trees or cars near
the chrome ball. (In general, outdoor scenes can contain buildings).
If you are using a single image of a chrome ball, map a File texture to the Ball
texture’s Image parameter, and then map the image file of the ball in the
environment to the File texture’s Image parameter.
If you are using a series of images of a chrome ball, map a Volume texture to
the Ball texture’s Image parameter, and then map one of the image files to
the Volume texture’s Pix Sequence parameter. Set the Volume texture’s From
and To parameters to the extensions of the first and last image files in the
sequence (1 and n).
Map the image of the environment without the chrome ball to the
environment’s Backdrop parameter.
Set the Ball texture’s Inclination and Elevation parameters to the inclination
and elevation of the camera used to photograph the ball.
For accurate reflections of the re-created environment on your model, set the
Ball texture’s Projection Geometry parameters to values corresponding to the
distance between any floor, walls, ceiling, or large objects and the chrome
sphere when it was photographed.
To simplify the positioning of the environment’s Backdrop image, set the Ball
texture’s Eyespace toggle ON. To model background geometry (for example,
so you can add shadows, lighting effects, or fog to your scene), set the Ball
texture’s Reflect toggle OFF.
The slider range is 0 to 20. The default value is 0.
Create a Cube environment
TIP To use a cube texture to simulate reflections from a real-world or CG
environment, from the center of the environment in all six directions either take
photographs of (real-world) or render (CG) the environment. Then map a cube
texture to a shader’s Reflection parameter, and assign the six images to the cube
texture. Scale and position the texture placement object so that it corresponds to
the dimensions of the original environment. Assign the shader to an object in your
scene and render (raycast). The object will appear to accurately reflect the original
environment.
Apply 3D environments | 93
One of the advantages of the cube environment texture is that you can blur
it without increasing rendering time.
Use Bluroffset to unfocus reflections when using the cube environment texture
as a reflection map to simulate unpolished surfaces.
The advantage to Cube environment maps is that they can be blurred as much
as you want without any additional computing cost. When you generate a
background from an environment map, the amount of blurring required to
prevent aliasing increases with the field of view. In practice, very little blurring
results when you use images with a 5122 texture and a field of view less than
90×.
For reflection mapped surfaces however, the amount of blurring depends on
the surface curvature and the distance from the eye point. This cannot be
computed automatically. Using the Blur_offset slider in the Blur window lets
you unfocus the reflections by a desired amount (see Common Surface Texture
Parameters for more information). In fact, soft-focus reflections can be used
to simulate less than perfectly polished surfaces.
NOTE In order to use a cube texture to map six image files onto the inner surface
of an infinite cube, you must set the ALIAS_INFINITE_CUBE environment variable.
See the Environment variables online documentation.
NOTE The reflections on a surface mapped with an infinite cube texture do not
change when you scale or move the surface or the texture placement object. The
reflections on a surface mapped with a finite cube do change when you scale or
move the surface or the texture placement object.
Add and edit lights
Learn how lighting a scene is an important part of the rendering workflow.
Create a light
Lighting creates mood, focus, and drama.
You can create a light using the Create light tools or using the Multi-lister.
You can use the light options to set properties for any new light you create.
By default, lights are named sequentially as you create them: Light, Light#2,
and so on. To avoid confusion, however, you should name all lights as you
create them. If you let the system assign default names and later combine two
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or more files, all lights are renumbered to avoid duplicate names. It may then
become difficult to distinguish lights by name.
NOTE Light#1 is not used explicitly as a name; the first light with a given name
is implicitly numbered 1.
To create a light using the Light tools
1 Select a tool from the Render > Create lights cascading menu, or click
one of these icons on the Create shelf:
NOTE If shelves are not visible choose Windows > Shelves.
2 Place the light by clicking in the modeling window, or by typing a set of
coordinates in the prompt line.
A new light swatch appears in the Multi-lister, and a new light icon
appears in the modeling window. Each type of light has a unique
modeling window icon and Multi-lister swatch.
In addition, light manipulators are displayed in the modeling window.
(To display the manipulators for an existing light, select the Pick > Object
tool, select the light, and select a Light tool.)
Add and edit lights | 95
Most lights have one manipulator that controls the light’s position. Spot
lights have two manipulators: one manipulator controls the light’s
position, the other manipulator controls its direction (look-at point).
Each manipulator consists of a square icon at its center, and three colored
arrow icons radiating from the center in the X, Y, and Z directions.
By dragging a square icon you can move the light or the light’s look-at
point across the view plane (in orthographic windows) or parallel to the
ground plane (in perspective windows). By holding the Alt key while you
drag a square icon you can snap the light to grid points.
By dragging an arrow icon you can move the light or the light’s look-at
point in the X, Y, or Z direction.
To create a light using the Multi-lister
■
In the Multi-lister (Render > Multi-lister > Lights), select Edit > New Light.
A new point light swatch appears in the Multi-lister, and a new point light
icon appears in the modeling windows at 0,0,0. Double-clicking the icon
opens up the Control Window that allows you to change the light type
and other parameters.
To display the light options box
Do one of the following:
■
Select Create lights from the Render menu, then click the box beside the
name of a light type (for example, Render > Create lights > Point r).
■
Double click one of the light icons from the Create shelf.
Related topics
Light parameters
Render > Create Lights > Point
Render > Create Lights > Spot
Render > Create Lights > Directional
Render > Create Lights > Ambient
Render > Create Lights > Area
Render > Create Lights > Volume
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Render > Create Lights > Linear
Render > Create Lights > Create defaults
Render > Editors > Light links
Display light icons
You can control whether light icons are displayed in the modeling windows.
To toggle the display of lights on or off
Select WindowDisplay > Toggles > Lights.
To open the Toggle Lights Options
Select WindowDisplay > Toggles > Lights r.
Animate lights
There are different ways of picking lights for animation, depending on which
parameters you want to animate.
To animate a light's transformations (translation, rotation, scale) or visibility,
pick the light in a modeling window or pick the appropriate light DAG node
in the SBD window.
To animate any other light parameter, such as color, intensity, or glow, pick
the light in the Multi-lister window. When animating a light through the
Multi-lister, the light should not be active in the modeling window unless its
transformations or visibility are also to be animated.
To copy all light animation from one light to another, select the root node of
one light, and use Animation > Edit > Duplicate animation channels r with
Hierarchy set to BELOW and Parameters set to ALL in the Duplicate Channels
Options box. The animation of individual light (or shader, or texture)
parameters can be copied by selecting the source light in the Multi-lister, doing
a Shift-select of the light to be copied to in the Multi-lister, and then
Shift-selecting the desired parameters in the light (or shade, or texture) editor.
Invoking Edit > Copy Parameters in the Multi-lister will then copy the
animation for that parameter.
Correct self shadows
The Self Shadow Correction parameters let you correct self-shadowing problems
that can occur with shadow casting spot lights during raycasting.
Add and edit lights | 97
NOTE To see the Self Shadow Correction Parameters in the Light control window
(which opens when you double-click a Light in the Multi-lister), you must have
Type set to Spot, and Renderer Shadows turned ON.
A spot light uses a shadow map (or depth map) to calculate the shadows cast
by surfaces. If a surface is illuminated by a spot light, then the shadow map
will begin at the illuminated surface and extend away from the light. Any
surface that lies within this shadow map will be in shadow.
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A problem may occur on illuminated, shadow casting surfaces. Because the
shadow map has a fixed resolution, it may not be smooth enough to describe
a surface. The shadow map may actually intersect the surface. This means that
the illuminated surface will be partially within its own shadow. The result is
a dark moire pattern on the surface.
To solve this problem you can set the Min Depth parameter to a small value.
The renderer will then temporarily move the shadow casting surface toward
the light, before calculating the shadow map, so the surface will no longer be
within its own shadow.
The problem with using Min Depth is that it may be difficult to know what
is too small a value and what is too large a value. If the Min Depth value is
too small, the surface will still be partially within its own shadow. If the Min
Depth value is too large, other surfaces which should be in shadow may no
longer be in shadow. Another problem is that the Min Depth value is in world
space units, so the magnitude of the value will depend on the scale of your
scene. Using Min Depth can also interfere with motion blur.
Add and edit lights | 99
Using Blend Offset is a better method of solving self-shadowing problems.
Whereas Min Depth moves the entire shadow casting surface an equal amount,
Blend Offset moves different surface points different amounts, based on the
probability that the original point on the shadow map was correct.
Self-shadowing can be even more of a problem with motion-blurred objects.
The renderer calculates motion blur by simulating the shutter and exposure
time of a real camera. The motion blurred object is rendered several times
between the shutter’s open and close times for each frame. The shadow map,
however, is only calculated at the shutter mid-point. If the object is moving
very fast away from the spot light, then it may appear to be entirely within
its own shadow for part of the motion blur.
Link a light
When you first create a light, its illumination is unrestricted. That is, depending
on the light’s type and parameters, it can potentially illuminate every surface
in your scene.
You may, however, want to restrict a light’s illumination by linking it to a
particular surface (or group of surfaces). If you link a light to a surface, that
surface will only be illuminated by that light; all other lights are ignored. If
the link is non-exclusive, the light will also illuminate other surfaces. If the
link is exclusive, the light will only illuminate the surface it is linked to.
You can link forces to objects using the same method for linking lights to
surfaces.
You can link a light to a surface using either the Link Lights tool in the
Multi-lister, or the Light Link Editor.
To link a light to a surface using the Multi-lister
1 Use Pick > Object to select the surface(s) you want to link.
2 In the Multi-lister, select the light you want to link to the active surface(s).
See Link Lights in Render > Multi-lister.
3 In the Multi-lister, select Shading > Link Lights.
To link a light to a surface using the Link Editor
1 Use Pick > Object to select the surface(s) and light(s) you want to link.
See Render > Editors > Light links.
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2 Select Render > Editors > Light links to open the Light Link Editor.
All active lights and surfaces are listed in the Components list (at the
lowest component level) and in the Picklist.
See Link in Render > Editors > Light links.
3 Click the Link button to link the lights and surfaces listed in the Picklist.
NOTE To change the list of lights and surfaces in the Picklist, see Render >
Editors > Light links.
NOTE An alert box is displayed if no lights or only lights are listed in the
Picklist. Make sure your selection includes both lights and surfaces.
To make a link exclusive
Use the control window on page 66
1 Open the light’s Control Window.
2 Set Exclusive Link ON.
To view a light link in the Objects window
1 In the Multi-lister, select the light you want view.
See List Objects in Render > Multi-lister.
2 In the Multi-lister, select Shading > List Objects. The Objects window
appears, listing all surfaces to which the active light is linked. Active
objects appear highlighted in the Objects window.
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To view a light link in the Link Editor
1 Use Pick > Object to select the linked surface(s) and light(s) you want to
view.
See Render > Editors > Light links.
2 Select Render > Editors > Light links to open the Light Link Editor.
3 Click the arrow (->) beside the surface or light in the Components list.
All surfaces/lights linked to that light/surface are listed in the Current
Links list.
To remove a light link using the Multi-lister (Method 1)
1 Use Pick > Object to select the surface(s) you want to unlink.
2 In the Multi-lister, select the light you want to unlink from the active
surface(s).
See Unlink Lights in Render > Multi-lister.
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3 In the Multi-lister, select Shading > Unlink Lights.
To remove a light link using the Multi-lister (Method 2)
1 In the Multi-lister, select the light you want to unlink.
2 In the Multi-lister, select Shading > List Objects. The Objects window
appears, listing all surfaces to which the active light is linked. Active
objects appear highlighted in the Objects window.
3 Hold the Shift key and click on the names in the Objects window until
all objects are highlighted.
See Unlink Lights in Render > Multi-lister.
4 In the Multi-lister, select Shading > Unlink Lights.
To remove a light link using the Link Editor
1 Use Pick > Object to select the linked surface(s) and light(s).
2 Select Render > Editors > Light links to open the Light Link Editor.
3 Select the linked surfaces and lights in the Components list so they appear
in the Picklist.
See Unlink in Render > Editors > Light links.
4 Click the Unlink button.
Add and edit cameras
Learn how to work with cameras.
Add and edit cameras | 103
Open the Camera Editor
The Camera Editor contains parameters which control the properties of cameras
and image planes. The title bar of the Camera Editor contains a keyframe
button which lets you set a keyframe for a parameter, and a model pick button
which lets you select the modeling window associated with the current camera
in the Camera Editor.
1 Select the modeling window for the camera that you want to edit.
2 Select Windows > Editors > Cameras.
The camera editor opens.
See the next sections for details on the parameters in this window:
■
Camera parameters in Windows > Editors > Cameras
■
Image Plane properties in Windows > Editors > Cameras
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Mimic the squeeze ratio for an anamorphic lens
1 In the Camera Editor, select the Anamorphic predefined film back, or
create your own film back.
2 In the Image File Output section of the Render Globals window, set the
X Resolution and Y Resolution to values appropriate for an anamorphic
lens (for example, 500 and 423), and set the Pixel Aspect Ratio to an
appropriate value (for example, 2). The Pixel Aspect Ratio (under Render
Globals) produces the same effect as the Squeeze Ratio (in the Camera
Editor).
3 Render your scene.
View the image file. Please note that this image file will be distorted.
Create or copy a camera
You use cameras to generate views for modeling windows and to generate
views to render.
Create a new camera by selecting View > New Camera.
Display camera icons
You can control whether camera icons are displayed in the orthographic
modeling windows.
Select WindowDisplay > Toggles > Cameras.
Change a camera’s view
You can change a camera’s view by changing its Camera Properties, Film Back
Properties, and Lens Properties. (see Camera Properties, Film Back Properties,
and Lens Properties in Windows > Editors > Cameras). You can also change a
camera’s view using the camera tools (see the tools in the View palette).
Zoom and Dolly
Both zooming and dollying change the size of all objects in your scene as they
appear in the camera’s window. Dollying, however, also changes the size of
objects that are near the camera relative to objects that are far from the camera.
Zooming maintains the relative size of objects in your scene. By dollying, you
are moving the physical location of the camera; by zooming, you are changing
the focal length of the camera’s lens.
Add and edit cameras | 105
Track and Film Back Offset
Both tracking and changing the film back offset value change the position of
all objects in your scene as they appear in the camera’s window. Tracking,
however, also changes the position of objects that are near the camera relative
to objects that are far from the camera. Changing the film back offset value
maintains the relative position of objects in your scene.
Animate a camera
You can animate a camera parameter setting in the Camera Editor by
Shift-clicking the name of the parameter, and then clicking the Key button
in the title bar of the Camera Editor. This is similar to the procedure for
animating parameter settings in the Control Window (see Animate parameters
on page 67). You can also animate a camera using Animation > Turntable,
Animation > Tools > Autofly or Animation > Keyframe > Set keyframe.
Select camera views to render
You can select which camera views will render an image file, mask file, or
depth file in the Render Globals window.
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To select which camera views will render
See Render > Globals.
1 Select Render > Globals to open the Render Globals window.
2 In the Image File Output section of the Render Globals window, set the
Image toggle on for the camera views you want to render as images. By
default, only perspective cameras have their Image toggle on. You can
also set the Mask and Depth toggles to select which camera views will
render as mask files or depth files.
A camera will not render an image file, mask file, or depth file if the
camera is invisible, regardless of its Image, Mask, and Depth toggle
settings.
Add and edit image planes
Learn how to work with image planes.
Add or delete an image plane
You can add any number of image planes to a camera.
You use image planes as visual references while building a model or as a means
of compositing background or foreground images during rendering.
To add an image plane to a camera using Import Image Plane
1 Select the modeling window of the camera you want to add an image
plane to.
2 Select File > Import > Image plane to open the File Requestor.
3 Use the File Requestor to select the image file you want to use as an image
plane, and click Load Image.
The image plane appears in the modeling window.
NOTE You cannot load image planes that have alphabetic characters in their
numeric extension (for example, an animated sequence having numeric
extensions). Make sure the extension only contains numbers. If the image
sequence consists of fields, use the filace utility to first interlace the fields into
frames.
Add and edit image planes | 107
To add an image plane to a camera using the Camera Editor
1 Select Windows > Editors > Cameras to open the Camera Editor.
2 At the top of the Camera Editor, set Camera to the camera you want to
add an image plane to.
3 In the Image Planes section of the Camera Editor, click the Add button
to open the File Requestor.
4 Use the File Requestor to select the image file you want to use as an image
plane, and click Load Image.
The image plane appears in the modeling window, and an image plane
swatch appears in the Image Planes section of the Camera Editor.
To delete one image plane from a camera
1 Select Windows > Editors > Cameras to open the Camera Editor.
2 At the top of the Camera Editor, set Camera to the camera you want to
delete an image plane from.
3 In the Image Planes section of the Camera Editor, select the swatch of
the image plane you want to delete, and click the Delete button.
The image plane is deleted from the camera’s window, and from the
image plane swatch list in the Image Planes section of the Camera Editor.
To delete all image planes from a camera
1 Select the modeling window of the camera you want to delete all image
planes from.
2 Select Delete > Delete image planes r to open the Delete Image Plane
Options box.
3 In the Delete Image Plane Options box, set Delete Type to Current
Window, and click Go.
All image planes are deleted from the active window.
To delete all image planes from all cameras
1 Choose Delete > Delete image planes r to open the Delete Image Plane
Options box.
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2 Set Delete Type to All Windows.
3 Click Go.
All image planes are deleted.
Name an image plane
Change the name of an image plane.
To rename an image plane
1 Choose Windows > Editors > Cameras to open the Camera Editor.
2 At the top of the Camera Editor, set Camera to the view that contains
the image plane you want to name.
3 In the Image Planes section of the Camera Editor, select the swatch of
the image plane you want to rename.
4 In the Image Plane Parameters section of the Camera Editor, set Name
to the name you want to use for the image plane.
Hide or show an image plane
Make an image plane visible, invisible, or show only an outline.
To hide or show an image plane
1 Choose Windows > Editors > Cameras to open the Camera Editor.
2 At the top of the Camera Editor, set Camera to the view that contains
the image plane you want to hide/show.
3 In the Image Planes section of the Camera Editor, select the swatch of
the image plane you want to hide/show.
4 In the Image Plane Parameters section of the Camera Editor, do one of
the following:
■
To hide the image plane, set Display Mode to Off.
■
To show the image plane, set Display Mode to Rgb.
■
To show only an outline of the extent of the image plane, set Display
Mode to Outline.
Add and edit image planes | 109
Adjust image plane brightness, contrast, and color
Dim, brighten, or color-correct an image plane.
If you are using na image plane as a reference for modeling, you may want to
reduce the brightness or contrast of the image plane to make it easier to see
3D objects. You can also adjust the overall colors of an image plane.
To dim all image planes
1 Choose WindowDisplay > Toggles > Image Planes r to open the Toggle
Image Planes Options box.
2 Set Display Toggle Type to Dim/Undim.
3 Set the RGB Mult and RGB Offset values that you want dimmed image
planes to be displayed with. The default values are 0.55.
4 Click Go.
NOTE This is the same as setting the image plane RGB Mult and RGB Offset
values in the Camera Editor for all image planes (see below).
NOTE To undim all image planes, choose WindowDisplay > Toggles > Image
Planes.
To adjust image plane brightness, contrast, or color
1 Choose Windows > Editors > Cameras to open the Camera Editor.
2 At the top of the Camera Editor, set Camera to the view that contains
the image plane you want to adjust.
3 In the Image Planes section of the Camera Editor, select the swatch of
the image plane you want to adjust.
4 In the Image Plane Parameters section of the Camera Editor, do any of
the following:
■
To adjust the brightness of the image plane, set the RGB Mult value.
■
To adjust the contrast of the image plane, set the RGB Offset value.
■
To multiply all colors in the image plane, click the RGB Mult color
chip to open the Color Editor and select a color.
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■
To offset all colors in the image plane, click the RGB Offset color chip
to open the Color Editor and select a color.
Move or scale an image plane
Move an image plane horizontally, vertically, or in front of or behind 3D
objects, or scale it.
You can move an image plane to change its position relative to its view. You
can also scale an image plane to change its size relative to its view. Moving
or scaling an image plane in this way changes the actual image plane, (that
is, it changes the number of pixels per inch [ppi]), but it does not change the
absolute size of the image plane (measured in pixels). This enables you to
make the image plane a "real world scale" -- for example, you can create an
automobile-sized image plane, with a defined resolution in pixels.
If you only want to change your view of an image plane, do not move or scale
it. Track or dolly into the view instead (using Alt Shift with the middle mouse
button or right mouse buttons.
You can also move an image plane so that it appears behind (background) or
in front of (foreground) the grid and 3D objects.
To move or scale an image plane interactively (using the Move or Scale
tools)
1 Choose Pick > Object types > Image plane.
2 Choose Transform > Move or Transform > Scale.
3 Click on the image plane in the view.
A manipulator appears on the image plane.
NOTE The manipulator will not appear if objects other than image planes
are selected (for example, surfaces).
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4 Drag a manipulator handle to move or scale the image plane, or click a
manipulator handle to select it (the handle will become white) and either:
■
drag anywhere in the view
■
press the arrow keys
■
type the horizontal and vertical values you want to move or scale the
image plane by and press Enter.
NOTE Choose Edit > Undo while the manipulator is still active to undo
the image plane transformation.
NOTE If you transform an image plane, the transformation will be applied
as you drag the manipulator.
NOTE The manipulator is centered on the image plane’s pivot point. To
adjust the position of the pivot point, use the Transform > Local > Set
pivot tool. To position the pivot point in the center of the image plane,
use the Transform > Local > Center pivot tool.
To move an image plane horizontally or vertically (using the Camera
Editor)
1 Choose Windows > Editors > Cameras to open the Camera Editor.
2 At the top of the Camera Editor, set Camera to the view that contains
the image plane you want to move.
3 In the Image Planes section of the Camera Editor, select the swatch of
the image plane you want to move.
4 In the Image Plane Parameters ; Image Placement section of the Camera
Editor, set the following parameters:
■
Bottom Left—The location of the bottom left corner of the image
plane (in the main linear unit). If you set the Bottom Left X (or Y)
value, the Top Right X (or Y) value automatically updates.
Set up for sketching
■
Top Right—The location of the top right corner of the image plane
(in the main linear unit). If you set the Top Right X (or Y) value, the
Bottom Left X (or Y) value automatically updates.
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To scale an image plane (using the Camera Editor)
1 Choose Windows > Editors > Cameras to open the Camera Editors
2 At the top of the Camera Editor, set Camera to the view that contains
the image plane you want to scale.
3 In the Image Planes section of the Camera Editor, select the swatch of
the image plane you want to scale.
4 In the Image Plane Parameters : Image Placement section of the Camera
Editor, set the horizontal or vertical Size value (measured in the main
linear unit) for the image plane.
If you set Image XY Ratio Lock to ON, the image plane is scaled
proportionally when you set one of the Size values; that is, when you set
the X value, the Y value automatically updates (and vice versa).
Set up AliasStudio for sketching
To move an image plane behind or in front of the grid and 3D objects
1 Choose Windows > Editors > Cameras r to open the Camera Editor
window.
2 At the top of the Camera Editor, set Camera to the view that contains
the image plane you want to move.
3 In the Image Planes section of the Camera Editor, select the swatch of
the image plane you want to move.
4 In the Image Plane Parameters : Image Placement section of the Camera
Editor:
■
Set the Depth parameter to Priority (ensuring that the Priority value
is a positive number) to move the image plane in front of the grid
and 3D objects.
■
Set the Depth parameter to Off, or set the Priority value to zero or a
negative number, to move the image plane behind the grid and 3D
objects.
The priority value that you assign to different image planes also
determines the order in which the image planes will appear in the view.
The plane with the largest priority value will be in front of all others, and
so on.
See Windows > Editors > Cameras for more details.
Add and edit image planes | 113
Crop or extend an image plane
Resize an image plane by cropping or extending.
To crop or extend an image plane
1 Open the Windows > Editors > Cameras option window.
2 At the top of the Camera Editor, set Camera to the view that contains
the image plane you want to crop/extend.
3 In the Image Planes section of the Camera Editor, select the swatch of
the image plane you want to crop/extend.
4 In the Image Plane Parameters section of the Camera Editor, double-click
one of the Pixels values.
The left value is the width of the image plane; the right value is the height.
5 Type a new value and press Enter.
The image plane is cropped or extended horizontally from the right or
vertically from the top (or both).
NOTE The Pixels parameter represents the horizontal and vertical size of the
image plane in pixels. When you set the Pixels values, the image plane is
extended or cropped (and the Size values are automatically updated).
Animate an image plane
You can animate an image plane using a variety of different methods:
■
Animate an image plane parameter setting in the Camera Editor by
Shift-clicking the name of the parameter, and then clicking the Key button
in the title bar of the Camera Editor. This is similar to the procedure for
animating parameter settings in the Control Window (see Animate
parameters on page 67).
■
Use a series of images as an animated image plane by setting the Frame
Type parameter in the Image section of the Camera Editor (see Frame Type
in Windows > Editors > Cameras).
■
Use Animation > Keyframe > Set keyframe.
114 | Chapter 3 How do I
Sizing and positioning an image plane
By default, an image plane fills the camera view with the entire image. You
can size and position an image plane so that only a portion of the image
appears or so the image appears in a specific region of the camera view.
Use the Image Placement parameters in the Camera Editor to size and position
an image plane (see Image Placement in Windows > Editors > Cameras), or
pick the image plane (Pick > Object types > Image plane) and use the Transform
tools to transform it.
Masking an image plane
You can mask an image plane so that only portions of the image are visible.
Use the Mask parameters in the Camera Editor to mask an image plane (see
Mask in Windows > Editors > Cameras).
Direct render a window
■
Select Render > Direct render. The Direct Render window appears on top
of the active window and renders the window’s view.
To stop a direct render, click in the Direct Render window.
To re-render a direct render, click the re-render icon in the Direct Render
window title bar.
To re-render a particular region of the direct render, click-drag a box in
the Direct Render window.
Set rendering quality on a per-object basis
Learn how to set rendering quality on individual objects.
1 In the modeling windows, select the objects whose rendering parameters
you want to edit.
2 Select Windows > Information > Render stats. The Render Stats window
appears.
Set rendering quality on a per-object basis | 115
Object Names list
The names of all active objects.
To edit or change an object name, double click on its name, (press the Esc key
to delete the entire name), type the new name and press Enter.
Use the horizontal scroll bar located below the object names list to view names
that are longer than the window view area.
Use the vertical scroll bar located along the left side of the window to scroll
through the list of object names when the list is too long to be viewed in the
window as a complete set.
Editing cells
The spreadsheet consists of several cells for each named object. Each cell can
be edited when not dimmed. Most cells can be toggled ON or OFF by clicking
directly in the cell. When an option is toggled ON, the cell displays a check
mark. When an option is toggled OFF, the cell displays a dash.
Some cells contain a numeric value. To edit a numeric cell, click directly in
the cell and then type a new value. Values larger than six digits to the left of
the decimal point are displayed in scientific notation. Pressing Enter confirms
the entry. Pressing Esc aborts the edit.
You can perform mathematical computations on numeric cells using the ‘c’
command. For example, say the current value for a field is 6. If you click in
that field, type c*2 and press Enter, the value will change to 12. If you type
c+7, the value will change to 13. If you type c-1, the value will change to 5.
If you type c/2, the value will change to 3.
116 | Chapter 3 How do I
Selecting rows
A single mouse click on an object name deselects all rows in the spreadsheet
and then selects that particular row.
Holding the Shift key and single-clicking on an object name selects that row
in the spreadsheet without affecting the current select state of any other row
in the spreadsheet.
Holding the mouse down on an unselected name and then dragging it down
the list selects the first row and all rows the mouse passes over. If one of the
rows that the mouse passes over is currently selected, it remains selected.
If multiple rows are selected, a change made to any one cell in any row
automatically affects the same cell in every other selected row. This greatly
reduces the time involved in making a change to multiple objects.
Render a scene using the current Rendering Options settings
1 Select Render > Render. The File Requestor appears.
2 Type the full path and file name for the rendered image in the File
Requestor, or click Show List and select the file using the File Lister. If
you select a file using the File Lister, the renderer will overwrite the file
with the rendered image file.
Render a scene using Ambient Occlusion
1 Turn on WindowDisplay > Hardware Shade.
2 Choose Render > Ambient Occlusion > Compute.
3 Render the scene.
After ambient occlusion is calculated using Hardware Shading, the
calculation is used (if it has not been toggled off with Render > Ambient
Occlusion > Toggle Display) for software rendering.
If you change your scene by changing or replacing surfaces or
transforming items, recalculate the ambient occlusion map and use
Hardware Shading before re-rendering.
View a rendered image
How to view a rendered image at actual size.
If the Render Monitor from the rendering is still open, click Show.
Set rendering quality on a per-object basis | 117
If you have closed the Render Monitor, choose File > Show image.
On Windows hardware, you can also select Animation > Show > FCheck. Then
in the FCheck window, select File > Open Image, and either:
■
type the name of the file
or
■
use the file browser to select the file name.
Stop a render in progress
■
To halt a render before it finishes, either close the Render Monitor window
or click the Abort button in the Render Monitor window.
■
Performing this action is non-recoverable; that is, you cannot restart the
render at the point where it finished: you need to start a new render.
Export an SDL file
How to save a Scene Description Language (SDL) file for editing and rendering.
1 Select File > Export > SDL. The File Requestor appears.
2 Type the full path and file name for the SDL file in the File Requestor, or
click Show List and select the file using the File Lister. If you select a file
using the File Lister, the SDL file will overwrite that file.
3 Click Save SDL.
To cancel the process, press Esc.
Note the following when exporting an SDL file:
■
Delete all non-referenced shaders before exporting an SDL file, because all
shaders, whether they are actually assigned to surfaces or not, are written
out to the SDL file.
■
When you export an SDL file, each perspective window will generate an
image (or series of images) when the SDL file is rendered, because each
perspective window has an associated camera.
The file name you use for the SDL file is also used within the SDL file to
specify the output image file name. For example, if the SDL file is named
Planet, then the camera section of the SDL file will contain:
pix = “pix/Planet”,
118 | Chapter 3 How do I
If there is a second perspective camera named camera2, the SDL file will
also contain:
pix =”pix/Planet_camera2”,
If you have more than one perspective window, but only want to render
an image (or series of images) from one of them, either edit the SDL file,
or pick all objects, lights, and only one camera, and then select File > Export
> Active as, and use that file to export an SDL file from.
■
By default, comments are not included in the SDL file. If you want
comments included, put the following line in your shell before starting
AliasStudio:
setenv ALIAS_SDL_LONGFORM 1
Edit an SDL file
■
To edit an SDL file, use the stand-alone utiity bsdl to convert the file to
text format, and use your favorite text editor. For information on the Scene
Description Language, please refer to the technical documentation section
of the online bookshelf. After you complete any edits to the file, run bsdl
on the file again to convert it back to binary format before rendering.
Create a line drawing rendering
How to use Hidden Line Rendering to create an image that looks like a line
drawing.
Hidden line rendering produces outline renderings of objects that are filled
with flat, unshaded color. Silhouettes of surfaces include the effect of any
bump or displacement maps.
Set the appearance of objects in the Hidden Line Rendering Parameters in the
Render > Globals window and in each shader’s Control Window. If Hidden
Line Parms in the Render Globals window is PER OBJECT, then the hidden
line renderer uses the Hidden Line Rendering Parameters in each object’s
shader (see Hidden Line Rendering Parameters in Render > Multi-lister). If
Hidden Line Parms is GLOBAL, then the hidden line renderer uses the Hidden
Line Rendering Parameters in the Render Globals window for all surfaces.
Hidden line rendering does not represent colors, textures, transparency,
reflections, or shadows. The exact Anti-aliasing Levels Minimum and Maximum
values (in the Render > Globals window) are not relevant during hidden line
rendering. Any value above 0 turns on hidden line anti-aliasing. You should
set the Post Filter parameter ON (in the Blur section of the Render > Globals
Set rendering quality on a per-object basis | 119
window) when using hidden line rendering (see “Post Filter” in Blur Effects
in Render > Globals).
Use a command line rendering program
You can render an existing SDL file from a command line by using one of the
stand-alone render programs: renderer, raytracer, powercaster, and
powertracer. By rendering from a command line you can render a batch of
several SDL files at the same time; the only limitation is the amount of swap
space available. (For this reason the stand-alone renderers are also referred to
as batch renderers.) You can also specify options during command line
rendering which will override internal variables in the SDL file. This lets you
change the behavior of the renderer without having to actually edit the SDL
file.
120 | Chapter 3 How do I
Troubleshoot
4
How to resolve your rendering problems.
Common rendering problems
This section covers problems where the rendering ends normally, but the
resulting image has problems.
Rendering ends prematurely
Some common causes include:
■
Not enough memory.
Do one of the following:
Optimization on page 136
■
■
Reduce memory usage.
■
Increase the amount of swap space on your system disk (see below).
When your system runs out of memory during rendering, it will use the
swap space on your system disk as virtual memory.
Multiple instances of the same polyset with linked-lights and multiple shaders
may cause the renderer to crash.
Copy the polysets instead of instancing them.
121
If either of these do not seem to be the cause of the problem, then do one or
all of the following:
■
Render from the command line using the -N option. This turns on the
diagnostic mode and notifies you of anomalies in the SDL file’s global
settings.
■
Open the .out file in the sdl directory. The problem may be as simple as
a missing texture file.
■
Open the errlog file (Utilities > Errlog) and check for the message rendering
error: exited with error code XXX. The XXX values are UNIX system error
codes (not to be confused with internal error codes). The numbers come
from the man page for signals (just type “man 5 signal”). Add 128 to the
man page’s numbers, and you get our exit code numbers. Out of memory
is SIGUSR1, and the man page says its number is 16. Thus our exit code
numbers read 128+16=144. Segmentation fault is 128+11=139, and so on.
Increase memory swapping
Problem: Increase the amount of swap space on your system disk.
NOTE You must have root access to increase the amount of swap space on your
system disk.
1 Create a file such that its file size represents the amount of swap space
you want on your system disk.
For example, to create a 200 MB file you would type the following in a
UNIX shell:
mkfile 200m <filename>
2 Using a text editor (for example, jot) open the file:
/etc/fstab
and add the following line to it:
<path+filename> swap swap pri=2 0 0
3 Either restart your computer, or type the following in a UNIX shell:
swap -a <filename>
Some other possible remedies include:
■
If the scene uses BOT files, make sure Texture Caching is turned on in the
Render Globals window.
122 | Chapter 4 Troubleshoot
Images that don’t exist take a long time to load
The interactive package attempts to locate an image file in all directories
specified by ALIAS_PIX_SEARCHPATH.
Reduce the number of directories in ALIAS_PIX_SEARCHPATH.
Rendering takes a long time
Optimization on page 136
Common shadow image problems
This section covers scene lighting and shadow mapping problems.
Shadows produced from shadow casting
Problem: Shadows produced from shadow casting have jagged shadow
boundaries.
Shadow map resolution is low.
Do one of the following:
■
Narrow the spread of the spot light so that it just barely covers the region
you want lit. This provides a higher accuracy to the shadow map to work
from. If you see banding artifacts, try increasing the Min Depth in the Self
Shadow Correction section of the light’s Control Window for the light's
shadow.
■
Increase the resolution of the shadow map as a final resort. Remember,
keeping large shadow maps increases memory usage.
Shadows from light fog
Problem: Shadows from light fog may appear incorrect for very thin objects,
or Light fog shadows shift over an animation.
See Fog samples in Fog (available in software renderings) Render > Multi-lister.
Increase the Fog samples for the spot light.
Soft shadows produced by raytracing
Problem: Soft shadows produced by raytracing are noisy.
Common shadow image problems | 123
Do one of the following:
See Use Shadow Map in Render > Multi-lister.
■
For spot lights, toggle Use Shadow Map ON so that the raycast shadows
are used.
See Shadow Samples in Render > Multi-lister.
■
Increase Shadow Samples.
surface when raycasting
Problem: A dark moire pattern on a surface when raycasting, or Incorrect
shadows on a surface when raycasting.
Correct self shadows on page 97
The renderer incorrectly believes that a surface is behind its shadow map.
Do one of the following:
■
Set Min Depth (in the Self Shadow Correction parameters) to a small
positive number (in AliasStudio grid units), for example 0.01, for shadow
casting spot lights. This temporarily moves the surface (by the Min Depth
value) when the renderer is calculating shadows. If Min Depth is too small,
the surface will still be behind the shadow map. If Min Depth is too large,
other surfaces that should be in the shadow may be moved in front of the
shadow map. Perform a test render, and adjust Min Depth until shadows
appear correct.
See Min Depth in Render > Create Lights > Spot.
■
Instead of using Min Depth (as above), use Blend Offset. This variable
scales the amount it moves each point on the surface based on the shadow
map samples.
See Blend Offset in Render > Create Lights > Spot.
Moving objects with motion blur
Problem: Incorrect shadows for moving objects with motion blur.
Shadows are not motion blurred. The renderer calculates an object’s shadow
map when the camera shutter is at midpoint. When the object moves, it may
move behind its own shadow map.
Do one of the following:
124 | Chapter 4 Troubleshoot
See Shadows in Render > Editors > Render stats.
■
If the object has a separate surface facing the shadow casting spot light,
set Shadows off for that surface (under Render Stats).
Correct self shadows on page 97
■
Increase Min Depth or Blend Offset (in the Self Shadow Correction
parameters) for shadow casting spot lights.
Common aliasing problems
This section covers aliasing problems.
Aliasing artifacts over an animation
Problem: Jaggies or roping, noisy images, shimmer or moiré-banding over an
animation.
Not all aliasing artifacts are caused by the same limitations, nor are they
resolved in the same manner. For example, increasing the Minimum and
Maximum Anti-aliasing Levels will not solve the problem optimally. Types of
aliasing include: geometry, textures, shadows, highlights, and motion blur.
Common surfaces problems
This section covers surface problems.
Surfaces against background
Problem: Surfaces have jagged edges against the background.
Composite Rendering may be ON.
Do one of the following:
See Composite Rendering in Render > Globals.
■
Set Composite Rendering OFF (under Render Globals).
See Anti-aliasing Levels in Render > Globals.
■
First increase Threshold under Render Globals. If the jagged edges persist,
increase Minimum and Maximum Anti-aliasing Levels.
Common aliasing problems | 125
Surface silhouettes or edges appear faceted
Problem: Surface silhouettes or edges appear faceted.
See Mesh Tolerance (cm) in Render > Globals.
Decrease the Mesh Tolerance value (under Render Globals).
Cracks appear between surfaces
Problem: Cracks appear between surfaces that should be aligned.
Do one of the following:
■
Attach the surfaces together using Object edit > Attach > Attach.
See Mesh Tolerance (cm) in Render > Globals.
■
Decrease the Mesh Tolerance value (under Render Globals).
Camera’s Auto Render Clip parameter
Problem: Choppy surface artifacts
See Auto Render Clip in Windows > Editors > Cameras.
If you are not rendering animation, or not using shadow maps, or not
outputting depth files, turn on the camera’s Auto Render Clip parameter.
See ClippingNear/Far in Windows > Editors > Cameras.
Otherwise, increase the camera’s ClippingNear value.
Common textures problems
This section covers texture problems.
File textures
Problem: File textures are very noisy and not anti-aliased well, or File textures
appear to shift or shimmer over an animation.
First check that the texture’s Blurmult value is non-zero. Next, change the file
texture’s Filter type. The default setting is BLEND. The best compromise
between speed and quality is QUADRATIC.
126 | Chapter 4 Troubleshoot
Procedural textures
Problem: Procedural textures are very noisy and not anti-aliased well, or
Procedural textures appear to shift or shimmer over an animation.
Do one of the following:
See Blur in Render > Multi-lister.
■
Increase the Blurmult or Bluroffset values for the texture.
See Convert to Pix and Filter in Render > Multi-lister.
■
Use Convert to Pix to convert the procedural texture to a file texture, and
change the Filter type to QUADRATIC.
Procedural texture differences
Problem: Procedural textures aren’t quite the same on different platforms.
Procedural textures, or anything that uses a random number generator, will
have minor differences from one platform to the next. For this reason, we
recommend that if you are rendering a sequence of images, render the entire
sequence on one platform.
Depth of Field
Problem: An in-focus object next to a blurry foreground/background (Depth
of Field ON) shows a jaggy artifact.
Render the blurry foreground/background separately, and composite.
Textures are distorted
Problem: Textures are distorted (stretched or squashed)
See Chord Length in Render > Multi-lister.
The surface may have uneven parameterization. Set Chord Length ON under
the texture’s Surface Placement parameters.
Common motion blur problems
This section covers motion blur problems.
Common motion blur problems | 127
Motion blur noise
Problem: Insufficient temporal sampling of shading or textures.
See MB Texture Samples in Render > Editors > Render stats.
If the texture looks grainy, increase MB Texture Samples (under Render Stats)
for the object. This will marginally increase rendering time.
See MB Shading Samples in Render > Editors > Render stats.
If the specular looks noisy, increase MB Shading Samples (under Render Stats)
for the object. This will noticeably increase rendering time; increase MB
Shading Samples only when absolutely necessary.
Large objects do not motion blur correctly
A large object that stretches way beyond the view is clipped by the renderer.
This clipping is done properly when the object is not motion blurred, but may
clip incorrectly when the object is motion blurred.
See Mesh Tolerance (cm) in Render > Globals.
■
Change the Mesh Tolerance value (under Render Globals).
Motion blur does not work
There are two possible causes:
■
If you are raytracing, this is a known limitation.
See Motion Blur in Windows > Editors > Cameras.
■
If only the camera is animated, and nothing else (that is, a flyby), make
sure that Motion Blur is ON for the camera (in the Camera Editor).
Rendering with motion blur
Problem: Rendering with motion blur produces grid-like artifacts, or Rendering
with motion blur causes triangles to disappear.
Some large triangles may extend beyond the camera and near clipping planes.
Objects may be too close together, causing interpenetrating problems for
motion blur.
Decrease the Mesh Tolerance value (under Render Globals). Move surfaces
that may be too close together further apart.
128 | Chapter 4 Troubleshoot
Using lights and motion blur
Problem: Spot light shadows and light projections do not motion blur.
This is a known limitation.
For shadows, blur the shadow by decreasing the Resolution (under Shadow
Casting parameters). For projector lights, apply a solid projection texture to
the object rather than using the light projection.
Solid textures do not motion blur correctly
This is a known limitation. Surface textures motion blur correctly.
See Convert Solid Tex in Render > Multi-lister.
If the moving object is a patch or a polyset with u,v parameterization, use
Convert Solid Tex and apply the pix file as a File texture.
See Project to UV - Apply Mapping in Render > Multi-lister.
If the moving object is a polyset without u,v parameterization (for example,
a ViewPoint model), apply the solid texture as a Projection texture, and perform
a Project to UV mapping (under the texture’s Polyset Surface(U,V) Definition).
Using warped objects and motion blur
Problem: Warped objects do not motion blur when warp parameters are
animated.
When a warp parameter is animated, the resulting changes in the shape of
the warped object are not motion blurred. An object moving through a warp
will be motion blurred correctly.
Move the object relative to the warp.
Transparent surfaces
Problem: Chatter in motion blurred textures moving behind transparent
surfaces.
Motion blurred textures moving behind transparent surfaces may show chatter
in the texture.
See MB Shading Samples in Render > Editors > Render stats.
Increase MB Shading Samples for the transparent surface.
Common motion blur problems | 129
Fast moving objects
Problem: Motion blurred textures may appear streaked or noisy for fast moving
objects.
Do one of the following:
See MB Texture Samples in Render > Editors > Render stats.
■
Increase MB Texture Samples for the textured surface.
See MB Shading Samples in Render > Editors > Render stats.
■
If the motion blur of specular highlights, bump maps or displacement
maps is noisy, increase MB Shading Samples for the textured surface. This
will increase rendering time, so try increasing MB Shading Samples by one
for each test render until the streaks or noise is eliminated.
Common glows problems
This section covers glow problems in the render.
Shader glow
Problem: Shader glow brightness changes during an animation, or Shader
glow brightness is different at different rendering resolutions
The shader glow auto exposure is adjusting the overall brightness of the scene
for each frame. When a glowing object enters or exits the frame, the glow
intensity of all objects will change.
The shader glow auto exposure causes a similar problem when rendering at
different resolutions. For example, shader glow brightness will be different in
a high resolution final render than in a low resolution test render.
Do one of the following:
See ShaderGlow in Render > Multi-lister.
■
Set Auto Exposure OFF (under the environment’s ShaderGlow parameters),
and adjust the environment shader’s ShaderGlow Glow Intensity and Halo
Intensity by hand until shader glows have the correct brightness.
■
Render the animation with Auto Exposure ON, and select a frame in which
the shader glow brightness looks correct. Render that frame only, again
with Auto Exposure ON. Open the out file (out.log in the sdl directory),
and find the Glow intensity normalization factor and the Halo
130 | Chapter 4 Troubleshoot
intensity normalization factor. Enter these two values in the
environment shader’s ShaderGlow Glow Intensity and Halo Intensity
parameters, and set Auto Exposure OFF.
If you are also rendering at different resolutions, you must also scale these
values based on the difference in resolutions (scale factor).
For example, if you are doubling the rendering resolution, the scale factor
would be 2.
Alternatively, figure out the factor by which the *number* of pixels in the
image increases, and multiply the glow by it.
i.e.: (1920 x 1280) / (720 x 486) = 7.023
Multiply your glow intensity by 7.023
Glow is missing from volume lights
Light from a volume light exists only within its volume. If the camera is not
within this volume, then glow is not rendered.
Do one of the following:
■
Make sure that the camera is within the volume light boundary. Use Display
> Tgl camera if necessary.
■
Create a glow-only point light at the same location as the volume light.
Light shining through objects
Problem: Linear and area lights shine through objects, or Light glow shines
through objects.
Linear and area lights do not attempt to detect if there are shadowing objects
between the light and the eye. All other light types compute this occlusion
factor.
See Hide Source in Render > Multi-lister.
■
Create a shader glow object with the same shape as the light, and set Hide
Source ON.
Common glows problems | 131
See Opacity in Render > Multi-lister.
■
Set Opacity to 0 for the light.
The radius of the light may be so large that it is never completely occluded
by the object that should be shadowing it.
See Light Radius in Render > Multi-lister.
■
Check the Light Radius (under Common Parameters). The default setting
is 1 (that is, two grid units in diameter). If Light Radius is large in relation
to the geometry in the scene, reduce Light Radius to a value comparable
to the size of the geometry.
Glows do not render
There is not enough memory for the renderer to calculate glows.
Do one of the following:
Optimization on page 136
■
Reduce memory usage.
See Hide Source in Render > Multi-lister.
■
Render glows separately. Set Hide Source ON under Glow parameters, and
enter the command setenv SEPARATE_GLOW_FILES 1 in the render shell.
Render the scene, and composite the two image files.
Common image planes problems
This section covers image plane problems.
Pixels shift in image plane animation
Make sure the size of the perspective window is an even multiple of the image
plane’s source image resolution.
Common miscellaneous object problems
This section covers miscellaneous object problems.
132 | Chapter 4 Troubleshoot
Roping artifacts on highlights
The hard-edged highlights that the standard Phong model produces (many
times magnified by a noisy bump map).
See Shading model in Render > Multi-lister and Post Filter in Render > Globals.
Use the Blinn shading model instead. Also try turning the Post Filter option
ON in the Blur Effects section of the Render Globals window.
Objects and raytracing
Problem: Transparent objects do not show the background when raytracing,
or Reflective objects do not reflect the background when raytracing
You may be using a 2D texture or image plane on the background. For raytraced
images, you must use either a flat color or an environment map for the
background for reflected/refracted rays to render correctly.
Use a Spherical or Ball environment with your texture or image applied to it.
Thin highlights have roping artifacts
This may be due to the hard-edged highlights that the standard Phong model
produces (many times magnified by a noisy bump map).
Do one of the following:
See Shading model in Render > Multi-lister.
■
Use the Blinn shading model.
See Post Filter in Render > Globals.
■
Set Post Filter ON in Render Globals.
Blended surfaces do not render
If part of a blended surface is visible, and another part is invisible, the surface
will not render. The invisible part of the surface is not written to the SDL file,
so the blend cannot be regenerated for each frame.
Make all parts of a blended surface visible.
Displacement mapping
Problem: Displacement mapping does not work for layered shaders.
Only the lowest available layered shader can apply a displacement map.
Common miscellaneous object problems | 133
Create a single displacement map and apply it to the lowest layered shader.
Chord Length texture maps
Problem: Chord Length texture maps do not display correctly in Shade Wire
mode.
If a surface with uneven parameterization and a checker texture map with
Chord length ON is Quick rendered, the texture looks even, as a result of the
chord space conversion. However, if the Quick render window is closed, and
the shaded wire icon in the icon of the texture is clicked on, the surface is
displayed as though Chord spacing is OFF.
BOT (block oriented texture) files
Problem: Renderer does not recognize BOT (block oriented texture) files directly
applied as texture maps.
See Texture Caching in Render > Globals.
Set Texture Caching ON under Render Globals.
Invisible instances of objects are visible
This is a known limitation.
Duplicate the object instead of instancing it.
Bump map using a file texture
Problem: Bump map using a file texture does not render as expected.
If the file has an alpha channel, then the alpha channel is used for bump
mapping. If the file does not have an alpha channel, the RGB color channels
are converted into a grayscale using a luminance calculation, and then used
for bump mapping.
Remove the alpha channel from the file texture.
Banding appears on low intensity objects
This is due to the 8-bit per color channel limitation.
Do one of the following:
■
Set Film Grain to 0.01 in the environment shader.
134 | Chapter 4 Troubleshoot
■
Alter the colors of the lights by random, fractional amounts from pure
integer values. For example, change (255,255,255) to (254.3,255.2,254.9).
Templated objects
Problem: Templated objects rendered in an animated sequence become visible.
This is a known limitation.
Depth of field produces aliasing
With depth of field, the edge of an object in focus against a very blurry
foreground or background sometimes shows aliasing.
Render foreground blurry elements separately and composite them.
Overall image problems
This section covers overall image problems.
Black borders (letter box) appears in render
The black borders define the film gate.
See Ignore Film Gate in Render > Globals.
Set Ignore Film Gate ON under Render Globals.
Rendering image matching views
Problem: The rendered image does not match the view in the modeling window
or camera.
There are several possible causes:
■
The rendering aspect ratio may be different than the modeling window
aspect ratio.
Set the window resolution to be the same as the rendering resolution.
■
The camera’s film offset may be greater than or equal to the camera’s film
back size.
■
You may have used Render Active, and the dag items under the camera
were not selected in whole.
Overall image problems | 135
■
You may be using motion path curves with knot multiplicity.
Rebuild the curve or select CurveTools > Use result from Animation >
Editors > Action window.
Color banding in rendered image
See Film Grain in Render > Multi-lister.
Set Film Grain to 0.01 in the environment control window.
Overall image is too sharp
See Post Filter in Render > Globals.
Set Post Filter ON under Render Globals, and set the Post Center, Post Adjacent
and Post Diagonal parameters to 4,2,1.
Incorrect lighting, view, or texture placement
Zero transforms for a light, camera, or 3D texture placement objects causes
problems.
Do not select Transform > Zero transforms for a light, camera, or 3D texture
placement object. If you do, you must go through the affected portion of the
hierarchy (the SBD window is useful for identifying this), and ungroup and
retransform the light, camera, or 3D texture placement object.
Optimization
Rendering a scene often takes a long time. There are, however, many methods
you can use to help reduce rendering times.
Raycaster/Raytracer optimization
Raycaster optimization
See Double Sided in Render > Editors > Render stats.
Wherever possible make surfaces single-sided.
136 | Chapter 4 Troubleshoot
Raytracer optimization
Avoid raytracing everything in your scene. For example, do not raytrace
transparent objects which do not require refraction.
See Shadows in Render > Editors > Render stats.
Avoid using area and linear lights that cast shadows.
See Raytrace Parameters in Render > Multi-lister and Raytracing Maximum
Limits in Render > Globals.
Minimize the number of levels of reflection, refraction and shadows either
globally (Maximum Reflections, Maximum Refractions, and Max Shadows
Levels in the Render Globals window) or by shader (Reflect Limit, Refract
Limit, and Shadow Limit in the shader’s Control Window). A setting of 1 is
usually sufficient. One bounce of reflection is sufficient for most mirror effects,
and more than 1 level of shadows tends to be wasteful. Even 2 levels of
reflection (combined with refraction) will substantially increase rendering
time.
See Reflection in Render > Multi-lister.
Where possible, use reflection maps instead of raytraced reflections.
Avoid huge floors with complex geometry occupying one small region. Scale
down the floor.
See Subdivide Recursion in Render > Globals.
If you have enough memory, try increasing the voxel Subdivide Recursion
value in the Render Globals window to higher values such as 3 or 4. Memory
use, however, may increase exponentially by doing this.
See Use Depth Map in Render > Multi-lister.
For spot lights that cast soft shadows, set Use Depth Map ON in the light’s
Control Window.
Modeling and shading
Model your scene based on the camera’s view, and make every element as
simple as possible for that view. For example, if your scene contains mountains
in the distance, don’t model them as displacements with lots of triangles and
complex shaders. Instead, use simple planes mapped with photos of real
mountains and with transparency maps for their profiles. To create a field of
asteroids, model some of the near asteroids, use bump maps for the smaller
ones, and use particles for the smallest ones. For the most distant asteroids,
use a few large planes with transparency, color, and bump maps.
Optimization | 137
See Transparency in Render > Multi-lister.
When building and trimming surfaces, use the minimum possible number of
CVs and isoparametric curves. Use transparency maps instead of trim surfaces
when possible.
See Mask and Depth in Render > Globals.
You may want to (or need to) create and render your scene in different layers
and then composite multiple renders using mask and depth files and a
compositor (for example, Maya Composer or Maya Fusion).
Backgrounds
See Color and Use Back Color in Render > Multi-lister.
If the background does not change during an animation, pre-render it and
use it as a backdrop by assigning the pre-rendered image to the Environment
Color parameter. You can cast shadows onto such a backdrop using the shader’s
Use Back Color parameter.
Do not use backdrops if you have a compositor (for example, Maya Composer
or Maya Fusion). Instead, composite the backdrop with the rendered scene.
Not only will this decrease rendering time, but if you make changes to your
scene elements, you won’t have to re-render the background.
Textures
See Blurmult, Convert to Pix, and Convert Solid Tex in Render > Multi-lister.
Adjust the Blurmult value to anti-alias textures rather than setting the
Anti-aliasing Levels values high. Only the File texture and some procedural
textures have a Blurmult parameter. For surface textures that do not have a
Blurmult parameter, try using the Convert to Pix button to convert the texture
to a pix file (with or without anti-aliasing); for solid textures that do not have
a Blurmult parameter, try using the Convert Solid Tex button to convert the
texture to a pix file (with or without anti-aliasing). Apply the pix file as a File
texture, and adjust the File texture’s Blurmult value.
See Rgboffset in Render > Multi-lister.
Instead of using a large, high resolution texture, try combining a large, low
resolution texture with a repeating small scale, high resolution texture for fine
detail. You can apply the small scale texture to the large scale texture as an
Rgboffset or an alpha offset. This can dramatically reduce memory usage.
Avoid using expensive procedural textures on surfaces that cover a large area
of the view. Among the worst offenders are the Granite, Leather, sFractal,
138 | Chapter 4 Troubleshoot
sCloud (with noise), Projection (with noise), Water (if the Numwaves value
is high or Reflect_bound. is ON), sWood (you will get better results using a
Projection texture with an image of a tree cross-section), and sMarble textures.
The Sky texture can also be expensive, especially if it uses Fractal or sFractal
clouds and ground.
When the blurmult is low and the level_max is high fractal noise can be very
slow (although you get nice detail). Try to convert expensive procedural
textures into small wrapping file textures where possible. Solid textures can
use convert solid texture in some cases. However, often it may be preferable
to render a square swatch of the solid texture (by putting the texture on the
environment shader color), and then using this swatch as a projection map.
Triplaner mapping sometimes works well.
You can convert the sky texture into a faster rendering ball texture by simply
rendering a square image of a sphere with the sky reflection map (specularity
1, reflectivity 1, color black). Make sure the sphere just touches the edges of
the view. This same trick can be used to pre-render raytrace reflections.
Avoid using procedural textures as bump maps, displacement maps, or per
pixel warps. These effects use five texture evaluations per sample (as opposed
to one for a color map). Even worse are cases where you have layer upon layer
of transparent surfaces with textures, such as a field of particles with an sFractal
blob map.
See Convert to Pix and Convert Solid Tex in Render > Multi-lister.
If you have several textures “chained” together (that is, textures mapped onto
textures), collapse them into a single File texture using either Convert to Pix
(for surface textures) or Convert Solid Tex (for solid textures).
If a solid texture takes too long to compute and you can afford the memory,
use Convert Solid Tex and apply the pix file as a File texture. This also gives
you better control over texture filtering.
See Texture Caching in Render > Globals (“bot” textures).
Make all File textures as small as possible. If you must use large texture maps,
use Texture Caching (under Render Globals).
Glow
See ShaderGlow in Render > Multi-lister.
If your scene contains shader glow, and you increase the resolution of your
render, lower the ShaderGlow Quality value proportionally.
Optimization | 139
Lights
Minimize the number of lights in your scene. Do not use lights if you can use
shader effects or textures instead. For example, to create highlights on a face’s
cheeks, do not create a linked point light above each cheek; instead, use shader
parameters like translucence and texturing to create the effect. To create a
marque of lights, don’t actually create 100 lights; use a textured shader instead.
You can get the marque highlights by using an environment map with a lot
of bright glow spots. Also ask if your effect should use a texture on a single
light rather then many lights.
See Render > Create Lights > Volume.
If you must use many lights in your scene, make them volume lights. Volume
lights do not calculate illumination for objects outside their volume, and will
render faster than other light types.
See Renderer Shadows in Render > Multi-lister.
Don’t make every light cast shadows; be selective.
See Depth Maps in Memory in Render > Globals and Use Depth Map in Render
> Multi-lister.
If shadows don’t change during an animation, reuse the shadow depth map
by setting Depth Maps in Memory ON (under Render Globals) or by using the
-k or -K1 option with the command line renderer. You can also reuse shadow
depth maps for individual spot lights by setting Use Depth Map ON (under
Shadow Casting).
Rendering parameters
It is not always necessary to render at your eventual output resolution. For
example, to match the blurriness of NTSC video you can render at a lower
resolution and resize the image up when compositing. Also, if you render soft
cloud particle elements separately, you may be able to use much smaller
renders, perhaps 1/4 your final output resolution with no anti-aliasing.
See Object rendering parameters in Render > Editors > Render stats.
Set the Object Rendering Parameters (MB Texture Samples and MB Shading
Samples) as low as possible for each object and for the camera view.
See Motion Blur in Render > Globals and Motion Blurred in Render > Editors
> Render stats.
140 | Chapter 4 Troubleshoot
Do not use motion blur for objects which do not move, or barely move, during
an animation. You can turn off motion blur either globally (under Render
Globals) or by object (under Render Stats).
See Shadows in Render > Editors > Render stats.
Avoid shadow casting surfaces. The fewer shadow casting surfaces there are,
the faster the shadow map generation/shadow casting will be. The smaller the
volume bound by all shadow casting surfaces, the higher the density of the
shadow maps (and the better the shadow quality).
See Anti-aliasing Levels in Render > Globals.
Keep the Anti-aliasing Levels as low as possible. They have a very strong
influence on rendering times. Use the following suggested values:
Quality
Minimum
Maximum
Low
0
0
Medium
0
4
High
3
12
Preview rendering
See Animation in Render > Globals.
Make sure Animation is OFF (under Render Globals). Parsing animation curves
can be very expensive.
See Render in Render > Globals.
If possible, set Render to ACTIVE (under Render Globals) so only active objects
are rendered.
Rendering
Do not run any other major process on your machine during rendering. If
possible, do not even run any other minor process (for example, wrl) during
rendering.
Watch memory usage closely and avoid going into swap at all costs (see
Reducing memory usage).
Optimization | 141
Memory usage
If after optimizing your scene using the above techniques, rendering may still
use all of your available memory and some swap.
When rendering a huge and complex scene, it is possible to run out of pointer
space, even if you have enough memory. A 32 bit processor cannot address
memory larger than 232-1, or about 2 gigabytes. But after you take away the
overhead of stack and heap, you’re left with about 1.8 gigabytes as the
maximum size of a 32 bit application.
Reducing memory usage
Make sure your system limits are set up to use all of the memory available to
you - “hinv” indicates RAM and “/etc/swap -ln” indicates swap sizes. To make
sure that all the RAM is made available to your process, type “limit” and see
if the RAM information matches. The mismatch usually occurs when you have
more than 256 megs of RAM on your machine.
Reduce the subdivision of insignificant surfaces (Windows > Render stats).
Reduce the tile-size (rendering command-line option of -T)—this will be useful
for all renderers except for the raytracer.
Make sure the resolution of your texture maps are of reasonable size for the
importance to the resultant rendering (for example, don't apply a 4kx4k texture
map to an insignificant object).
Reduce the resolution of your shadow maps (Multi-lister > Light > Shadows).
Don't use the raytracer/powertracer unless you really have to—these
applications eat up more memory than the raycaster.
Reduce the memory used by file textures
For File textures, set FILTER to OFF. This avoids allocating extra memory when
filtering for the texture map; however, this can produce aliasing artifacts.
See Filter in Render > Multi-lister.
Turn Texture Caching ON under Render Globals, and set Disk Cache Limit to
a size larger than necessary to hold all your textures. This can dramatically
reduce the running size of a rendering job. The job will use a lot more
temporary disk space, but less memory.
Or, you can add the following lines to the DEFINITION section of the SDL
file:
142 | Chapter 4 Troubleshoot
texture_caching = ON;
texture_cache_size = 32;
texture_cache_disk_limit = <maximum space to use for textures>;
Increase the amount of temporary disk spaced available for file textures by
using the command line renderer with the -l option. The value specified after
-l indicates the amount of TMPDIR disk space the renderer can use for file
textures. Increasing the TMPDIR disk space frees up some RAM for the renderer.
(TMPDIR is the environment variable that indicates the location of the
temporary disk space.)
Use the command line renderer
Use File > Export SDL to save the SDL file for your scene. Exit the interactive
package, and use the command line renderer to render the SDL file.
Reducing memory usage while Raytracing
Set the grid_cache value in the DEFINITION section of the SDL file to something
smaller than 4000. Try decreasing grid_cache by 500 between test renders,
until grid_cache is 1000, then try decreasing it by 100 between test renders.
Reduce the Subdivide Recursion limit value in the Raytracing Maximum Limits
section of the Render Globals window (under Global Quality Parameters)—
but realize that a big performance hit can be the end result if you do this.
Optimization | 143
144
Index
2D mapping 73
2D textures 8, 73
3D mapping 73
3D spaces 32
simulating 32
3D textures 32, 85
simulating 32, 85
A
adding 66, 107
color to color blending palette 66
color to color palette 66
image planes to a camera 107
aliasing 94, 125
common problems 125
preventing 94
alligator skin, simulating 27
ambient lights 42
anamorphic lens 105
squeeze ratio 105
animating 67, 106, 114
cameras 106
image planes 114
parameters 67
animation 69
icon in control window 69
icon in multi-lister swatch 69
area lights 42
Assign Current Shader 60–61, 63
assign to a surface 60
change a shader 60
layer shaders 63
modify color 61
assigning 58, 70
shaders 58
textures 70
automobiles 34
showroom reflection 34
B
backgrounds 32, 138
for scenes 32
optimizing 138
reducing rendering times 138
ball texture 93
accurate reflections 93
balls 92
reflective 92
batch rendering 120
Blinn shader 59
reflections 59
blurs 94
blur offset for reflections in cube
texture 94
brick, simulating 39
bulge texture 10
surface texture 10
C
camera parameters 115
lens properties 115
cameras 44–45, 105–108
adding image planes 107
animating 106
changing view 105
copying 105
creating 105
deleting image planes 108
displaying icons 105
dollying 105
film back offsetting 106
image planes 45
orthographic 44
perspective 44
selecting views to render 106
tracking 106
zooming 105
145 | Index
canvas planes 109
sketch 109
canvases 109
cast iron, simulating 27
cells, simulating 39
changing 52, 64
colors 64
multi-lister swatches 52
chroma key masking 72
chrome 17, 25, 92
ball 92
dents 25
simulating 17
chrome texture 34, 36
sky parameters 36
clouds 13, 23–24, 81
layers, simulating 24
simulating 23, 81
simulating fractal 13
solid texture 23
color 61
intensity 61
modify 61
palette 61
color blending palette 66
adding color 66
color editor 63, 65–66
customizing 66
opening 63
overview 63
undoing changes 65
color palette 61, 66
adding color 66
colors 64–66
adding to color blending palette
adding to color palette 66
editing 64
grabbing from screen 65
selecting 64
setting current color 64
setting HSV 64
setting RGB 64
undoing changes 65
command line rendering 120
concrete, simulating 27
146 | Index
control window 66–67, 69
animating the parameters 67
animation icon 69
copying parameter settings 66
in Multi-lister 66
parallelogram (icon) 69
title bar 66
convert to smear 87
overwriting files 87
converting 39
2D to 3D texture 39
copying 55, 65–66, 105
cameras 105
colors from screen 65
lights 55
parameter settings in control
window 66
shaders 55
cowhide, simulating 13
Create Layered Shader 63
tool to layer shaders 63
creating 54, 69, 92, 94, 105
cameras 105
chrome ball image 92
keyframe for multi-lister
parameters 69
lights 54, 94
shaders 54
cube texture 35
D
66
default 43, 58
lighting 43
shader 58
deleting 56, 107
image planes from a camera
lights 56
shaders 56
textures 56
direct render 115
commands 115
directional lights 41
dirty 10
windows simulating 10
107
displaying 37, 70, 97, 105
camera icons 105
light icons 97
texture placement objects 37, 70
displaytgls menu 97
object toggles > lights 97
distortion 71
surface textures 71
dollying 105
cameras 105
E
earth (planet), simulating 24
editing 55, 64
colors 64
environments 55
lights 55
shaders 55
textures 55
effects 10–11, 13–17, 19–20, 22–25, 27,
30, 39, 42, 59, 81–83
alligator skin 27
brick 39
cast iron 27
cells, living 39
chrome 17
chrome dents 25
cloth 11
clouds 13, 23, 81
concrete 27
cowhide 13
dirty windows 10
eggshell 16
explosions 83
eyeball 17
fabric 11
feathers 17
fire 23, 83
flames 13, 82
fractals 24
fur 17
geometric patterns 17
glows 83
hair 17
headlight 14
lava 25
leather 27
lights, fluorescent 42
marble 19, 25
mesh 17
mottled surfaces 17
mountains 13
mud 13
plastic window 14
rain 13
reflections 20, 59
rippled glass 16
ripples in water 20
rock 13, 19, 27
sand 20
smoke 23, 83
snow 22
snow-capped mountains 15
steam 23
stoplight 10
stripes 17
styrofoam 27
tail light 30
tiles 10
underwater 20
water ripples 20
waves 20
window 14
wood 30
wood grain 19
eggshell, simulating 16
environment textures 7, 32, 34–36, 69,
93
ball 93
chrome 34
cube 35
definition 32
positioning 69
sky 36
sphere 36
types 32
environments 53, 55–56, 66–67, 69, 91
animating 67
changing name 56
control window 91
copying settings 66
Index | 147
editing 55
keyframes for 69
loading 56
playing back animation
saving 56
selecting 53
swatch 91
exclusive lights 100
links 100
explosions 83
simulating 83
eyeball, simulating 17
eyedropper 75
using 75
glows 83, 130, 139
common problems 130
optimizing 139
reducing rendering times
simulating 83
grabbing 65
colors 65
granite texture 29
69
H
hair
17
simulating 17
headlights, simulating 14
height, sketch image plane 113
HSV 64
setting 64
F
fabric, simulating 11
feathers, simulating 17
file menu 48
edit SDL 48
export >SDL 48
file texture 9, 81, 83
converting solid texture to 83
files 72, 87
masking 72
overwriting 87
film back offset value (cameras) 106
fire 23, 83
simulating 23, 83
flames, simulating 13, 82
fluorescent lights, simulating 42
focus of reflections 94
changing 94
fractal 24
solid texture 24
fur, simulating 17
G
geometric patterns, simulating
geometry 125
common problems 125
glass 16
rippled 16
148 | Index
139
17
I
icons 69, 97
animation in multi-lister 69
of lights 97
image files 9, 85
for texture 9
used for 3D texture 85
image plane 111
manipulator 111
image planes 45, 107–108, 114–115
adding to a camera 107
animating 114
deleting from a camera 107–108
masking 115
overview 45
positioning 115
sizing 115
image problems 135
images 123, 126
problems with 123, 126
incandescent lights, simulating 41
infinite cube 94
mapping six images to 94
interrupting 118
rendering 118
K
key button 69
in control window 69
keyframes 69
environments, lights, shaders, &
textures 69
L
label mapping 71
label masking 72
chroma key 72
file 72
Lambert shader 81
for clouds 81
lava 25
layering shaders 58
leather 27
simulating 27
leather texture 27
solid texture 27
lens 105
anamorphic 105
lens properties 115
camera 115
light links 101–102
making exclusive 101
removing 102
viewing in Link Editor 102
viewing in Objects window 101
light reflections, simulating 20
lights 41, 43, 53–56, 66–67, 69, 94–97,
100–103, 140
animating 67
changing name 56
copying 55
copying settings 66
creating 54, 94
default 43
deleting 56
displaying icons 97
editing 55
exclusive links 100
icons 97
incandescent 41
keyframes for 69
light options 96–97
linking 100, 103
linking to surfaces 100
loading 56
making links exclusive 101
manipulators 95
naming 55
non-exclusive links 100
optimizing 140
options 97
playing back animation 69
reducing rendering times 140
removing links 102
restricting illumination 100
saving 56
selecting 53
types 95
types defined 41
unlinking 103
viewing links in Link Editor 102
viewing links in Objects
window 101
linear lights 42
link editor 100
using 100
linking 100, 103
lights 100, 103
loading 56
environments 56
lights 56
shaders 56
textures 56
M
manipulator 95, 111
image plane 111
on lights 95
mapping 70
textures to parameters
marble 19, 25
solid texture 25
masking 72, 115
image planes 115
labels 72
70
Index | 149
stencil texture 72
memory usage 142
optimizing 142
reducing 142
reducing rendering time 142
menus 4
rendering 4
mesh, simulating 17
modeling 137
optimizing 137
reducing rendering times 137
modeling windows 37
cube with arrow 37
motion blur 100, 128
and self-shadowing 100
common problems 128
noise 128
mottled surfaces, simulating 17
mountains 13, 15
simulating 13
snow-capped 15
mud, simulating 13
multi-lister 51–53, 60, 69
animation icon 69
assign a shader 60
changing display of swatches 52
definition 51
opening 51
overview 51
parallelogram icon in swatch 69
playing back animation 69
selecting swatches 53
N
naming 55
lights 55
shaders 55
non-exclusive lights
links 100
100
O
object names list 116
render stats 116
150 | Index
opening 69
texture procedures window
optimization 136, 143
optimizing 6
rendering time 6
orthographic camera 44
69
P
parallelogram 69
in multi-lister swatch 69
parallelogram (icon) 69
animation of parameter 69
parameters 66–67
animating 67
copying in control window 66
perspective camera 44
Phong shader 59
reflections 59
planes 45
image planes 45
planets, simulating 24
plastic windows, simulating 14
playback 69
animated environment 69
animated light 69
animated shader 69
animated texture 69
point lights 41
point of view 36
too low 36
polysets 85
re-parameterizing 85
positioning 69, 72, 115
environment textures 69
image planes 115
solid textures 69
surface textures 72
powercasting 47
definition 47
powertracing 47
definition 47
preview rendering 141
optimizing 141
reducing rendering times 141
previewing 48
render 48
projection texture
tools 88
39, 88–89
R
rain
13
simulating 13
range fields 64
HSV 64
RGB 64
raycasting 47, 59, 136
definition 47
optimizing 136
reducing rendering times 136
reflections 59
raytracing 47, 59, 137
definition 47
optimizing 137
reducing rendering times 137
reflections 59
re-parameterizing polysets 85
reflection 20, 59
mapping a shader 59
water 20
reflections 59, 93–94
ball texture 93
Blinn shader 59
Phong shader 59
simulating 59
unfocus using bluroffset 94
refraction 20
from water 20
renaming 56
swatches 56
render 48
preview 48
render globals 47
render menu 48
direct render 48
render stats 47
rendered image 117
viewing 117
rendering 3–6, 36, 47, 106, 118, 120–
121, 123, 136, 141, 143
a scene 5
aborting a render in progress 118
batch 120
command line 120
definition 3, 5
ends prematurely 121
global parameters 47
menu summary 4
object parameters 47
optimization 136, 143
optimizing 141
problems with 121, 123
red sky texture 36
reducing rendering times 141
selecting camera views 106
stand-alone 120
summary of controls 5
takes a long time 123
time, minimizing 6
tools for 4–5
workflow 3
rendering parameters 47, 140
optimizing 140
overview 47
reducing rendering times 140
Resident Shaders 63
layer shaders 63
RGB 64
setting 64
ripples 16, 20
in glass, simulating 16
simulating 20
rock 13, 19, 27
simulating 13, 27
solid texture 27
S
sampling 65
colors 65
sand, simulating 20
saving 56
environments 56
lights 56
Index | 151
shaders 56
textures 56
SBD 60
assign a shader 60
SBD window 38
texture placement object 38
scene backgrounds 32
Scene Description Language 48
SDL 48
SDL files 48
exporting to 48
selecting 53, 64
colors 64
environments 53
lights 53
shaders 53
textures 53
self shadow correction 97
spot light 97
self-shadowing 100
and motion blur 100
shaders 53–56, 58–61, 63, 66–67, 69
animating 67
assign 60
assigning to surface 58
change 60
change a color 61
changing name 56
copying 55
copying settings 66
creating 54
customize 59
default 58
deleting 56
display 60
editing 55
keyframes for 69
layer 63
layering 58
libraries 59
loading 56
middle mouse button 59
modify color 61
modify intensity 61
move 59
naming 55
152 | Index
playing back animation 69
reflection mapping 59
Resident Shaders 61
saving 56
selecting 53
Shader Parameters 61
shading 137
optimizing 137
reducing rendering times 137
shadows 123–125
common problems 123, 125
dark moire pattern 124
incorrect light fog shadows 123
jagged boundaries 123
raytracing problems 123
shift over an animation 123
showroom environment 34
size 113
sketch image plane 113
sizing image planes 115
sketch image planes 113
height 113
size 113
width 113
sky parameters 36
chrome texture 36
sky texture 36
red 36
smoke 23, 83
simulating 23, 83
snow 15, 22
on mountains 15
solid texture 22
snow, simulating 22
solid textures 7, 21, 69, 83
converting to file texture 83
positioning 69
types 21
sphere texture 36
spot lights 41, 97, 100
and self-shadowing 100
self shadow correction 97
stand-alone renderers 120
steam, simulating 23
stoplight, simulating 10
stopping 115, 118
direct render 115
rendering 118
stripes, simulating 17
styrofoam, simulating 27
surface textures 7–10, 32, 71–73, 81
2D mapping 73
bulge 10
chroma key masking 72
definition 32
distortion 71
file 9, 81
file masking 72
file texture 9
label mapping 71
label masking 72
positioning 72
types 9
using 8
surfaces 58, 71, 80
applying image file 71
applying label 71
assigning shaders 58
layering 58
shaders on objects 58
mapping 71
masking 71
texture placement 80
swap space 122
increasing 122
swatches 52, 56
changing in multi-lister 52
renaming 56
T
tail light 30
Terra, simulating 24
texture 24
texture files 9, 81
texture placement 80
texture placement objects 36–38, 70
displaying 70
SBD window 38
toggling visibility 70
transforming 37
texture procedures 36, 69
texture types 36
texture procedures window 69
opening 69
texture types 36
texture procedures 36
textures 7–9, 22–25, 27, 29–31, 36–37,
53, 55–56, 66–67, 69–70, 72–73,
126–127, 138
2D 8, 73
2D mapping 73
animating 67
assigning 70
blurry artifacts 127
changing name 56
common problems 126
copying settings 66
cube with arrow on swatch 37
deleting 56
determining origin and direction 36
distorted 127
editing 55
environment 7
inverted 70
keyframes for 69
loading 56
mapping 70
masking stencil texture 72
optimizing 138
parameters 73
playing back animation 69
positioning 69
reducing rendering times 138
saving 56
selecting 53
solid 7
solid cloud 23
solid fractal 24
solid granite 29
solid leather 27
solid marble 25
solid rock 27
solid snow 22
solid volume 31
solid wood 30
surface 7, 73
Index | 153
texture placement icon 37
toggling texture placement
objects 70
transforming placement 37
types 7, 36
upside-down 70
using image files 9
three-dimensional spaces 32
simulating 32
tiles, simulating 10
Toggle Shade 60, 63
display shaders 60
layer shaders 63
tools 88
projection texture 88
tracking cameras 106
troubleshooting 12, 32, 36, 97
aliasing on cloth textures 12
environment texture mapped to
Bump 32
environment texture mapped to
Displacement 32
moire patterns on cloth textures
red sky texture 36
self-shadowing problems 97
two-dimensional textures 8, 73
154 | Index
volume lights
42
W
12
water 20
simulating 20
water texture 20
parameters 20
waves 20
simulating 20
width, sketch image plane 113
windows 14
simulating 14
windows menu 45
edit > cameras 45
wood 19, 30
simulating 30
solid texture 30
wood grain effect 19
workflows 3
rendering 3
Z
zooming 105
cameras 105
U
underwater, simulating
V
20
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