Rhinoceros®

Rhinoceros®
Rhinoceros
“
NURBS modeling for Windows
Version 4.0
User’s Guide
Rhinoceros version 4.0
Copyright © 1993 - 2006 Robert McNeel & Associates. All rights reserved.
Printed in U.S.A.
Rhinoceros is a registered trademark and Rhino is a trademark of Robert McNeel & Associates.
All other brand or product names are registered trademarks or trademarks of their respective holders.
i
T A B L E
O F
C O N T E N T S
Table of Contents
NURBS Modeling...........................................................................................1
Viewports .....................................................................................................2
Viewport Title Menu ................................................................................... 2
Viewport Display Modes .............................................................................. 2
Mouse Navigation ...................................................................................... 3
Viewport Projection .................................................................................... 3
Modeling Aids ...............................................................................................4
Cursor Crosshairs, Marker, and Tracking Line................................................. 4
Grid Snap ................................................................................................. 4
Ortho Mode............................................................................................... 4
Distance Constraint.................................................................................... 5
Angle Constraint........................................................................................ 5
Elevator Mode ........................................................................................... 5
Coordinate Systems......................................................................................7
Cartesian Coordinates ................................................................................ 7
World Coordinates ..................................................................................... 7
Construction Planes ................................................................................... 7
Relative Coordinates .................................................................................. 8
Object Snaps ..............................................................................................10
Persistent Object Snaps ............................................................................ 10
SmartTrack............................................................................................. 11
Rhino’s Geometry Types .............................................................................12
Point Objects .......................................................................................... 12
Curves ................................................................................................... 12
Surfaces................................................................................................. 12
Polysurfaces ........................................................................................... 15
Solids .................................................................................................... 15
Polygon Mesh Objects .............................................................................. 16
Edit Curves and Surfaces ............................................................................17
Join ....................................................................................................... 17
Explode.................................................................................................. 17
Trim and Split ......................................................................................... 17
Control-Point Editing ................................................................................ 17
Curve and Surface Degree ........................................................................ 18
Transforms .................................................................................................19
Move ..................................................................................................... 19
Copy...................................................................................................... 19
Rotate.................................................................................................... 19
Scale ..................................................................................................... 19
Mirror .................................................................................................... 19
Orient .................................................................................................... 19
Array ..................................................................................................... 19
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T A B L E
O F
C O N T E N T S
Curve and Surface Analysis ........................................................................20
Measure Distance, Angle, and Radius.......................................................... 20
Curve and Surface Direction ...................................................................... 20
Curvature ............................................................................................... 20
Visual Surface Analysis ............................................................................. 21
Edge Evaluation....................................................................................... 22
Diagnostics ............................................................................................. 22
Organizing the Model .................................................................................23
Layers.................................................................................................... 23
Groups................................................................................................... 23
Blocks.................................................................................................... 23
Worksessions .......................................................................................... 24
Annotation .................................................................................................25
Dimensions............................................................................................. 25
Text....................................................................................................... 25
Leaders .................................................................................................. 25
Annotation Dots ...................................................................................... 26
Hidden Line Removal................................................................................ 26
Notes..................................................................................................... 26
Render........................................................................................................27
Lights .................................................................................................... 27
Render Mesh........................................................................................... 27
Tutorial: Solids and Transforms..................................................................28
Enter Coordinates .................................................................................... 28
Draw the Pull Toy Body ............................................................................ 28
Draw the Axles and Wheel Hubs ................................................................ 29
Draw the Lug Nuts ................................................................................... 30
Assign Colors .......................................................................................... 32
Array the Lug Nuts................................................................................... 32
Draw the Tires ........................................................................................ 33
Mirror the Wheels .................................................................................... 33
Draw the Eyes......................................................................................... 35
Make the Pull Cord................................................................................... 36
Tutorial: Revolve Curves.............................................................................39
Create a Free-Form Flashlight Model........................................................... 39
Set Up the Model ..................................................................................... 39
Draw a Centerline .................................................................................... 40
Draw the Body Profile Curve...................................................................... 40
Draw the Lens Profile Curve ...................................................................... 41
Build the Flashlight Body .......................................................................... 41
Create the Lens ....................................................................................... 42
Assign Properties and Render .................................................................... 42
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T A B L E
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C O N T E N T S
Tutorial: Sweep, Loft, and Extrude .............................................................44
Create the Speaker Shell .......................................................................... 44
Extrude a Curve into a Solid ...................................................................... 45
Join the Surfaces Together........................................................................ 47
Create the Padding .................................................................................. 47
Create the Mounting Bracket ..................................................................... 48
Create the Headband ............................................................................... 50
Create the Speaker Wire........................................................................... 54
Mirror the Headphone Parts....................................................................... 56
Tutorial: Point Editing and Blend Surfaces..................................................58
Create the Body and Head ........................................................................ 58
Create and Place the Eyes......................................................................... 61
Create the Beak ...................................................................................... 62
Create the Feet ....................................................................................... 64
Create the Tail ........................................................................................ 67
Create the Wings ..................................................................................... 69
Finishing Touches .................................................................................... 71
Apply Render Materials ............................................................................. 72
Tutorial: Loft a Boat Hull ............................................................................73
Lay Out the Hull Curves ............................................................................ 73
Check for Fairness ................................................................................... 74
Create the 3-D Curves.............................................................................. 75
About the Curves..................................................................................... 76
Loft the Hull Surfaces ............................................................................... 76
Trim the Bow and Bottom ......................................................................... 77
Build the Transom ................................................................................... 78
Complete the Transom ............................................................................. 80
Add the Deck .......................................................................................... 80
Tutorial: Trace Images ...............................................................................84
Draw the Body ........................................................................................ 84
Draw the Head ........................................................................................ 87
Blend the Head and Body.......................................................................... 88
Draw the Eyes......................................................................................... 89
Shape the Tail ......................................................................................... 90
Trace the Wings and Legs ......................................................................... 90
Tutorial: Wrap Curves on a Surface ............................................................92
Make a Surface ....................................................................................... 92
Create the Objects to Wrap ....................................................................... 93
Control the Placement of the Objects .......................................................... 93
Tutorial: Blends and Trims..........................................................................96
Create Basic Body Shape .......................................................................... 98
Blend the Front and Back Edges................................................................100
Trim the Body for the Viewfinder...............................................................103
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T A B L E
O F
C O N T E N T S
Create the Viewfinder..............................................................................105
Blend between the Body and the Viewfinder ...............................................107
Create Bottom of Camera ........................................................................108
Create the Lens and Blend between the Body and the Lens ...........................110
More Help .................................................................................................113
Help on the Internet................................................................................113
v
N U R B S
M O D E L I N G
NURBS Modeling
NURBS (non-uniform rational B-splines) are mathematical representations that can accurately
model any shape from a simple 2-D line, circle, arc, or box to the most complex 3-D freeform organic surface or solid. Because of their flexibility and accuracy, NURBS models can be
used in any process from illustration and animation to manufacturing.
NURBS geometry is an industry standard for designers who work in 3-D where forms are free
and flowing; where both form and function is important. Rhino is used in marine, aerospace,
and automobile interior and exterior design. Makers of household and office appliances,
furniture, medical and sports equipment, footwear, and jewelry use Rhino to create free-form
shapes.
NURBS modeling is also widely used by professional animators and graphic artists. The
advantage over using polygon modelers is that there are no facets. The models can be
rendered at any resolution. A mesh can be created from the model at any resolution. For
more information about the mathematics of NURBS, see the Rhino Help topic.
1
V I E W P O R T S
Viewports
The viewport title has some special functions for manipulating the viewport.
x
x
x
Click the title to make the viewport active without disturbing the view.
Drag the viewport title to move the viewport.
Double-click the viewport title to maximize the viewport. Double-click again to restore
the size to normal.
Viewport Title Menu
Right-click any viewport title to display a menu. From this menu, pan, rotate, zoom, set one
of the standard views, set a construction plane, set the camera and target locations, choose a
shading option, set the grid, and set other viewport properties.
Viewport Display Modes
Wireframe display usually offers the fastest display speed. Standard and customized shaded
modes allow easier visualization of surfaces and solids.
Wireframe Display
In wireframe view, surfaces look like a set of
crossing curves. These curves are called
isoparametric curves or isocurves.
Isocurves do not define the surface the way
the polygons do in a polygon mesh. They are
merely a visual aid.
The WireframeViewport command sets the
viewport display to wireframe.
Shaded Display
Shaded modes display surfaces and solids with
the surfaces shaded using their layer, object,
or custom color. You can work in any of the
shaded modes. The surfaces are opaque or
transparent.
The ShadedViewport command sets the
viewport display to shaded mode.
2
V I E W P O R T S
Rendered Display
Rendered viewport display shows the objects
with lighting and render materials applied
The RenderedViewport command sets the
viewport display to rendered mode.
Other display modes and custom settings are
described in the Rhino Help.
Mouse Navigation
Working in 3-D on a computer requires visualizing three-dimensional objects drawn on a
two-dimensional medium—the computer screen. Rhino provides tools to help do this.
Drag with the right mouse button to easily manipulate the views to look at the model from
various angles. Use the right mouse button view manipulations in both wireframe and shaded
views.
Viewport Projection
Viewports can have one of two projections: parallel or perspective.
Right mouse navigation works differently in the two viewport styles. In parallel views, rightmouse dragging pans the view. In perspective views, right-mouse dragging rotates the view.
In the usual four-viewport layout, there are three parallel viewports and one perspective
viewport.
Parallel
Parallel views are also called orthogonal
views in some systems. In a parallel view,
all the grid lines are parallel to each other,
and identical objects look the same size,
regardless of where they are in space.
Perspective
In a perspective view, grid lines converge
to a vanishing point. This provides the
illusion of depth in the viewport.
Perspective projection makes objects
farther away look smaller.
3
M O D E L I N G
A I D S
Modeling Aids
The cursor can always move freely in space, but chances are, you will want to relate your
modeling elements to the construction plane grid or to existing objects. You can restrict the
cursor’s movement to the grid, enter specific distances and angles from a point, and snap to
specific locations on existing objects.
Cursor Crosshairs, Marker, and Tracking Line
There are two parts of the cursor: the cursor (1) and the
marker (2). The cursor always follow the mouse movement.
The marker sometimes leaves the center of the cursor
because of some constraint on it such as grid snap or ortho.
The marker is a dynamic preview of the point that will be
picked when the left mouse button is clicked.
When the marker is constrained, in elevator mode, for
example, a tracking line (3) also displays.
Constraints move your marker to a specific point in space or
make its movement track according to the constraint so you
can model accurately.
Grid Snap
Grid snap constrains the marker to an imaginary grid that extends infinitely. You can set the
snap spacing to any value.
Click the Snap button on the status bar to turn grid snap on and off.
Ortho Mode
Ortho mode constrains the marker movement or object dragging to a specific set of angles.
By default, this is parallel to the grid lines, but you can change this. Ortho is similar to the
axis lock function found in drawing or animation programs.
Click the Ortho pane on the status bar to turn ortho on and off. Press and hold the Shift key
to temporarily toggle the ortho mode.
Another common use for ortho is to constrain object dragging to a specific axis.
Ortho is active after the first point for a command. For example, after picking the first point
for a line, the second point is constrained to the ortho angle.
Ortho off.
Ortho on.
If you only need a different angle for a single operation, angle constraint is faster to use.
Enter a specific angle for one operation instead of changing the ortho angle and then
changing it back.
4
M O D E L I N G
A I D S
Distance Constraint
When entering points, you can constrain the
marker to a distance from the previous point.
Once you have set the distance, drag the line
around to any angle. You can also use further
snaps to point the line in a specific direction.
During any command that requires two points,
such as the Line command, place the first point.
Then at the next prompt, type a distance and
press Enter or the Spacebar.
The marker will be constrained to the specified
distance from the previous point. Drag the
cursor around the first point and then pick a
point.
You can also constrain the marker to track on lines radiating from the previous point and
separated by a specified angle. The first constraint line is counterclockwise from the
construction plane x-axis.
Angle Constraint
Angle constraint is similar to ortho, but you can set any angle and it is a one-time setting.
The < symbol is used because it is similar to the ‘ symbol used in geometry to indicate an
angle.
The marker will be constrained to lines radiating from the previous point separated by the
specified angle, where the first line is the specified number of degrees counterclockwise from
the x-axis. If you enter a negative number, the angle will be clockwise from the x-axis.
Distance and Angle Together
Distance and angle constraints can be used at the same time. Type the distance at the
prompt and press Enter, and then type < and then the angle and press Enter. The order of
the distance and angle does not matter. The marker will drag around your original point at
angle increments at the specified distance.
Elevator Mode
To move the marker in the construction plane
z-direction, hold the Ctrl key and click a point
on the construction plane, and then drag
vertically from the construction plane and click
to pick a point. This constraint is called
elevator mode. Using elevator mode to move
your pick point vertically from the construction
plane lets you work more in the Perspective
viewport.
5
M O D E L I N G
A I D S
Pick a second point to specify the z-coordinate
of the desired point. It is easiest to see this in
a different viewport or use the Perspective
viewport. Drag the mouse cursor around to
see the marker move vertically from the base
point along the tracking line.
Pick the point with the mouse or type the
height above the construction plane. Positive
numbers are above the construction plane;
negative numbers are below it. You can use
further constraints like coordinates, object
snaps or grid snap for the first point, and you
can use object snaps for the height.
6
C O O R D I N A T E
S Y S T E M S
Coordinate Systems
Rhino uses two coordinate systems: construction plane coordinates and world coordinates.
World coordinates are fixed in space. Construction plane coordinates are defined for each
viewport.
Cartesian Coordinates
When Rhino prompts you for a point, if you type x and y Cartesian coordinates, the point will
lie on the construction plane of the current viewport. For more information about coordinate
systems and numeric constraints, see the Rhino Help topic, “Unit Systems.”
Right-Hand Rule
Rhino follows what is called the right-hand rule. The right-hand
rule can help you determine the direction of the z-axis. Form a
right angle with the thumb and forefinger of your right hand.
When your thumb points in the positive x-direction, your
forefinger points in the positive y-direction, and the palm of
your hand faces in the positive z-direction.
World Coordinates
Rhino contains one world coordinate system. The world coordinate system
cannot be changed. When Rhino prompts you for a point, you can type
coordinates in the world coordinate system.
The arrow icon in the lower left corner of each viewport displays the
direction of the world x-, y-, and z-axes. The arrows move to show the
orientation of the world axes when you rotate a view.
Construction Planes
Each viewport has a construction plane. A
construction plane is like a tabletop that the
cursor moves on unless you use coordinate
input, elevator mode, or object snaps or a few
other instances where input is constrained. The
construction plane has an origin, x- and y-axes,
and a grid. The construction plane can be set to
any orientation. By default, each viewport’s
construction plane is independent of those in
other viewports.
The construction plane represents the local
coordinate system for the viewport and can be
different from the world coordinate system.
Rhino’s standard viewports come with construction planes that correspond to the viewport.
The default Perspective viewport, however, uses the world Top construction plane, which is
the same construction plane that is used in the Top viewport.
The grid lies on the construction plane. The dark red line represents the construction plane
x-axis. The dark green line represents the construction plane y-axis. The red and green lines
meet at the construction plane origin.
7
C O O R D I N A T E
S Y S T E M S
To change the direction and origin of a construction plane, use the CPlane command. Preset
construction planes (World Top, Right, and Front) give you quick access to common
construction planes. In addition, you can save and restore named construction planes and
import named construction planes from another Rhino file.
2-D construction plane coordinates
`
At a prompt, type the coordinate in
the format x,y where x is the
x-coordinate and y is the y-coordinate
of the point.
A line from 1,1 to 4,2.
3-D construction plane coordinates
`
At a prompt, type the coordinate in the format x,y,z where x is the x-coordinate, y is
the y-coordinate, and z is the z-coordinate of the point.
There are no spaces between the coordinate values.
To place a point 3 units in the x-direction, 4 units in the y-direction, and 10 units in
the z-direction from the construction plane origin, type 3,4,10 at the prompt.
Note
If you enter only x- and y-coordinates, the point will lie on the construction plane.
Relative Coordinates
Rhino remembers the last point used, so you can enter the next point relative to it. Relative
coordinates are useful for entering a list of points where the relative locations instead of
absolute locations of the points are known. Use relative coordinates to locate points according
to their relationship to the previous active point.
Relative coordinates
`
At a prompt, type the coordinates in the format rx,y where r signifies that the
coordinate is relative to the previous point.
For example
1
Start the Line command.
2
At the Start of line… prompt, click to place the first end of the line.
8
C O O R D I N A T E
3
S Y S T E M S
At the End of line… prompt, type
r2,3, and press Enter or the
Spacebar.
The line is drawn to a point 2 units in
the x-direction and 3 units in the
y-direction from the last point.
9
O B J E C T
S N A P S
Object Snaps
Object snaps constrain the marker to specific points on an object. When Rhino asks you to
specify a point, you can constrain the marker to specific parts of existing geometry. When an
object snap is active, moving the cursor near a specified point on an object causes the
marker to jump to that point.
In this chapter you will learn:
x
x
x
x
How
How
How
How
to
to
to
to
use object snaps to find specific points on geometry.
set, clear, and suspend persistent object snaps.
use one-time object snaps.
use object snaps in combination with other modeling aids.
Object snaps can persist from pick to pick, or can be activated for one pick only. Multiple
persistent object snaps can be set from the status bar. All object snaps behave similarly, but
snap to different parts of existing geometry. In addition, there are special object snaps that
work for one pick only.
Persistent Object Snaps
Use persistent objects snaps to maintain an object snap through choosing several points.
Since persistent object snaps are easy to turn on and off, you can set them and leave them
on until they get in your way. You can then set a different one or just disable them.
Sometimes object snaps interfere with each other and with grid snap or ortho. Object snaps
normally take precedence over grid snap or other constraints.
There are other situations where object snaps work in conjunction with other constraints. You
will see examples of this in this chapter. For more information including video
demonstrations, see the Help topic “Object Snaps.”
To turn persistent object snaps on and off
1
On the status bar, click the Osnap pane.
2
In the Osnap toolbar, check or clear the desired object snaps.
To suspend all persistent object snaps
`
In the Osnap toolbar, click the Disable button.
All persistent object snaps will be suspended, but remain checked.
To clear all persistent object snaps
`
In the Osnap toolbar, click the Disable button with the right mouse button.
All persistent object snaps will be cleared.
To turn on one object snap and turn all others off with one click
In the Osnap toolbar, right-click the object snap you want to turn on.
10
O B J E C T
S N A P S
SmartTrack
SmartTrack™ is a system of temporary reference
lines and points that is drawn in the Rhino
viewport using implicit relationships among
various 3-D points, other geometry in space, and
the coordinate axes' directions.
Temporary infinite lines (tracking lines) and
points (smart points) are available to object
snaps very much like real lines and points.
You can snap to intersections of the tracking
lines, perpendiculars, and directly to smart
points as well as intersections of tracking lines
and real curves. The tracking lines and smart
points are displayed for the duration of a
command.
For more information including video demonstrations, see the Help topic “SmartTrack.”
11
R H I N O ’ S
G E O M E T R Y
T Y P E S
Rhino’s Geometry Types
Rhino’s geometry types include: points, NURBS curves, polycurves, surfaces, polysurfaces,
solids (closed surfaces), and polygon meshes. Surfaces and polysurfaces that enclose a
volume define solids. Rhino creates polygon meshes for rendering, surface analysis, and for
importing and exporting models to other applications.
Point Objects
Point objects mark a single point in 3-D
space. They are the simplest objects in
Rhino. Points can be placed anywhere in
space. Points are most often used as
placeholders.
Curves
A Rhino curve is similar to a piece of wire. It
can be straight or wiggled, and can be open or
closed.
A polycurve is several curve segments joined
together end to end.
Rhino provides many tools for drawing curves.
You can draw straight lines, polylines that
consist of connected line segments, arcs,
circles, polygons, ellipses, helixes, and spirals.
You can also draw curves using curve control
points and draw curves that pass through
selected points.
Curves in Rhino include lines, arcs, circles, free-form curves, and combinations of these.
Curves can be open or closed, planar or non-planar.
Surfaces
A surface is like a rectangular stretchy rubber
sheet. The NURBS form can represent simple
shapes, such as planes and cylinders, as well
as free-form, sculptured surfaces.
All surface creation commands in Rhino result
in the same object: a NURBS surface. Rhino
has many tools for constructing surfaces
directly or from existing curves.
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R H I N O ’ S
G E O M E T R Y
T Y P E S
All NURBS surfaces have an inherently
rectangular organization. Even a closed
surface such as a cylinder is like a rectangular
piece of paper that has been rolled up so two
opposite edges are touching. The place where
the edges come together is called the seam. If
a surface does not have a rectangular shape,
either it has been trimmed or the control
points on the edges have been moved.
Closed and Open Surfaces
A surface can be open or closed. A cylinder
without the ends capped is closed in one
direction.
A torus (donut shape) is closed in two
directions.
Surface Control Points
The shape of a surface is defined by a set of
control points that are arranged in a
rectangular pattern.
Trimmed and Untrimmed Surfaces
Surfaces can be trimmed or untrimmed. A
trimmed surface has two parts: a surface that
underlies everything and defines the
geometric shape, and trimming curves that
mark sections of the underlying surface that
are removed from view.
Trimmed surfaces are created with commands
that trim or split surfaces with curves and
other surfaces. Some commands create
trimmed surfaces directly.
Since it can be important for you to know if a surface is trimmed, the Properties command
lists the trimmed or untrimmed state of the surface. Some Rhino commands work only with
untrimmed surfaces and some software does not import trimmed NURBS surfaces.
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R H I N O ’ S
G E O M E T R Y
T Y P E S
Trimming curves lie on the underlying surface.
This surface may be larger than the trim
curves, but you will not see the underlying
surface because Rhino does not draw the part
of the surface that is outside the trim curves.
Every trimmed surface retains information
about its underlying surface geometry. You
can remove the trimming curve boundaries to
make the surface untrimmed with the Untrim
command.
If you have a trim curve that runs across a
surface, the trim curve itself does not have
any real relationship to the control point
structure of the surface. You can see this if
you select such a trimmed surface and turn its
control points on. You will see the control
points for the whole underlying surface.
If you create a surface from a planar curve, it
can be a trimmed surface. The illustrated
surface was created from a circle. The control
points display shows the rectangular structure
of the surface.
The Untrim command removes the trimming
curve from the surface to get back to the
underlying untrimmed rectangular surface.
14
R H I N O ’ S
G E O M E T R Y
T Y P E S
Surface Isoparametric and Edge Curves
In wireframe view, surfaces look like a set of
crossing curves. These curves are called
isoparametric curves or isocurve. These curves
help you visualize the shape of the surface.
Isoparametric curves do not define the surface
the way the polygons do in a polygon mesh.
They are merely a visual aid that allows you to
see the surface on the screen. When a surface
is selected, all of its isoparametric curves
highlight.
Edge curves bound the surface. Surface edge
curves can be used as input to other
commands.
Isocurves
Edge curves
Polysurfaces
A polysurface consists of two or more surfaces
that are joined together. A polysurface that
encloses a volume of space defines a solid.
Control points cannot be displayed on
polysurfaces, but the polysurfaces can be
exploded into surfaces, which can be edited
separately, and then rejoined.
Solids
A solid is a surface or polysurface that
encloses a volume. Solids are created anytime
a surface or polysurface is completely closed.
Rhino creates single-surface solids and
polysurface solids. A single surface can wrap
around and join itself (sphere, torus, and
ellipsoid). Control points can be displayed on
single-surface solids and moved to change the
surface.
Some Rhino commands for creating solid
primitives create polysurface solids. Box, cone,
truncated cone, and cylinder are examples of
polysurface solids.
15
R H I N O ’ S
G E O M E T R Y
T Y P E S
Polygon Mesh Objects
Because there are many modelers that use
polygon meshes to represent geometry for
rendering and animation, stereolithography,
visualization, and finite element analysis, the
Mesh command translates NURBS geometry
into polygonal meshes for export. In addition,
the Mesh creation commands draw mesh
objects.
Note: There is no easy way to convert a mesh model into a NURBS model. The information
that defines the objects is completely different. However, Rhino has a few commands
for drawing curves on meshes and extracting vertex points and other information
from mesh objects to assist in using mesh information to create NURBS models.
16
E D I T
C U R V E S
A N D
S U R F A C E S
Edit Curves and Surfaces
The editing operations in this section break objects apart, cut holes in them, and put them
back together. Some of these commands connect curves to curves or surfaces to surfaces or
polysurfaces and break a composite curve or polysurface into its components.
The commands: Join, Explode, Trim, and Split apply to curves, surfaces, and polysurfaces.
The Rebuild, ChangeDegree, and Smooth commands alter the shape of a curve or surface
by changing its underlying control point structure.
In addition, objects have properties that are assigned to them such as color, layer, rendering
material, and other attributes depending on the object. The Properties command manages
these properties.
Join
The Join command connects curves or surfaces together into one object. For example, a
polycurve can consist of straight-line segments, arcs, polylines, and free-form curves. The
Join command also connects adjacent surfaces into a polysurface.
Explode
The Explode command removes the connection between joined curves or surfaces. For
polysurfaces, this is useful if you want to edit each individual surface with control points.
Trim and Split
The Trim and Split commands are similar. The difference is when you trim an object, you
select the parts to remove and they are deleted. When you split an object, all parts are left.
The Split command will split a surface with a curve, surface, polysurface, or its own
isoparametric curves.
The Untrim command removes a surface’s trimming curve, with an option to keep the curve
so you can re-use it.
Control-Point Editing
You can make subtle changes in the shape of a curve or surface by moving the location of its
control points. Rhino offers many tools for editing control points. Some commands such as
Rebuild, Fair, and Smooth offer some automated solutions for redistributing control points
over a curve or surface. Other commands, such as control point dragging and nudging, HBar,
and MoveUVNOn, let you manually control the location of individual or groups of control
points.
Control Point Visibility
To edit curves and surfaces by manipulating control points, use the
PointsOn (F10) command to turn the control points on.
When you are finished with control-point editing, use the PointsOff
command or press Esc to turn them off.
Control points of polysurfaces cannot be turned on for editing. Editing
the control points of polysurfaces could separate the edges of the
joined surfaces creating “leaks” in the polysurface.
Change Control Points Locations
When you move control points, the curve or surface changes, and Rhino smoothly redraws it.
The curve or surface is not drawn though the control points rather it is attracted to the new
positions of the control point. This allows the object to be smoothly deformed. When control
points are on, Rhino’s transform commands can manipulate the points. You can also rebuild
surfaces to add control points and redistribute them.
17
E D I T
C U R V E S
A N D
S U R F A C E S
Add, Delete, or Redistribute Control Points
Adding control points to a curve gives you more control over the shape of the curve.
Manipulating control points also lets you remove kinks, make curves uniform, and add or
subtract detail. The Delete key erases curve control points. This changes the shape of the
curve.
Curve and Surface Degree
A polynomial is a function like y = 3·x3 –2·x + 1. The "degree" of the polynomial is the
largest power of the variable. For example, the degree of 3·x3 –2·x + 1 is 3; the degree of –
x5 + x2 is 5, and so on. NURBS functions are rational polynomials and the degree of the
NURBS is the degree of the polynomial. From a NURBS modeling point of view, the (degree –
1) is the maximum number of "bends" you can get in each span.
For example:
A degree-1 curve must have at least two control
points.
A line has degree 1. It has zero "bends."
A degree-2 curve must have at least three control
points.
A parabola, hyperbola, arc, and circle (conic section
curves) have degree 2. They have one "bend."
A degree-3 curve must have at least four control
points.
A cubic Bézier has degree 3. If you arrange its control
points in a zig-zag shape, you can get two "bends."
18
T R A N S F O R M S
Transforms
Transforms change the location, rotation, number and shape of whole objects by moving,
mirroring, arraying, rotating, scaling, shearing, twisting, bending, and tapering. The
transform commands do not break the objects into pieces or cut holes in them.
For more information and animated demonstrations, see the Help topic for each command.
Move
Use the Move command when you want to move an object a certain distance or if you want
to use object snaps to place an object accurately. The quickest way is to click the object and
drag it.
To move selected objects small distances, press and hold the Alt key and press an arrow key
to activate the Nudge feature.
Copy
The Copy command makes copies of objects.
Some transform commands like Rotate, Rotate 3-D, and Scale have a Copy option. This
lets you create a copy of the object as you rotate or scale it.
To copy objects by dragging, hold the Alt key and then drag the objects.
Rotate
The Rotate command rotates an object in relation to the construction plane.
Scale
Scale commands give you control over the direction of the scale. You can resize objects
uniformly in one, two, or three directions, or scale an object with a different scale factor in
each direction.
Mirror
The Mirror command reverses the orientation of the object across a defined line. By default,
a copy is made.
Orient
The orient commands combine move or copy, scale, and rotate operations to help you
position and size objects in one command.
Array
Copies objects into evenly spaced rows and columns.
19
C U R V E
A N D
S U R F A C E
A N A L Y S I S
Curve and Surface Analysis
Since Rhino is a mathematically accurate NURBS modeler, tools that provide accurate
information about the objects are provided.
Measure Distance, Angle, and Radius
Some analysis commands provide information about location, distance, angle between lines,
and radius of a curve. For example:
x
x
x
x
x
Distance displays the distance between two points.
Angle displays the angle between two lines.
Radius displays the radius of a curve at any point along it.
Length displays the length of a curve.
EvaluatePt displays coordinate information for any point.
Curve and Surface Direction
Curves and surfaces have a direction. Many commands that use direction information display
direction arrows and give you the opportunity to change (flip) the direction.
The Dir command displays the direction of a
curve or surface and lets you change the
direction.
The illustration shows the curve direction
arrows. If the direction has not been changed,
it reflects the direction the curve was originally
drawn. The arrows point from the start of the
curve toward the end of the curve.
The Dir command also displays surface u-, v-,
and normal direction. Surface normals are
represented by arrows perpendicular to the
surface, and the u- and v-directions are
indicated by arrows pointing along the surface.
Closed surfaces always have the surface
normals pointing to the exterior.
The Dir command can change the u-, v-, and
normal-directions of a surface. This direction
can be important if you are applying textures
to the surface.
Curvature
Curve analysis tools let you turn on a graph showing the direction perpendicular to the curve
at a point and the amount of curvature, display a curvature circle, test the continuity between
two curves and the intervals of overlap between the two curves.
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C U R V E
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A N A L Y S I S
The CurvatureGraphOn command displays a
curvature graph on curves and surfaces. The
lines on the graph represent a direction
perpendicular to the curve at that point. The
length of the line indicates the curvature.
Visual Surface Analysis
Visual surface analysis commands let you examine surfaces to determine smoothness as
determined by its curvature, tangency, or other surface properties. These commands use
NURBS surface evaluation and rendering techniques to help you visually analyze surface
smoothness with false color or reflection maps so you can see the curvature and breaks in
the surface.
The CurvatureAnalysis command analyzes
surface curvature using false-color mapping. It
analyzes Gaussian curvature, mean curvature,
minimum radius of curvature, and maximum
radius of curvature.
The EMap command displays a bitmap on the
object so it looks like a scene is being
reflected by a highly polished metal. Tool
helps you find surface defects and validate
your design intent.
The fluorescent tube environment map
simulates tube lights shining on a reflective
metal surface.
The Zebra command displays surfaces with
reflected stripes. This is a way to visually
check for surface defects and for tangency and
curvature continuity conditions between
surfaces.
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C U R V E
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A N A L Y S I S
The DraftAngleAnalysis command displays
by false-color mapping the draft angle relative
to the construction plane that is active when
you start the command.
The pull direction for the DraftAngleAnalysis
command is the z-axis of the construction
plane.
Edge Evaluation
Geometry problems such as Boolean or join failures can be caused by edges on surfaces that
have become broken or edges between surfaces that have been moved through point editing
so they create holes. An edge is a separate object that is part of the surface’s boundary
representation.
The ShowEdges command highlights all the
edges of the surface.
Find the Open Edges on a Polysurface
A polysurface may look closed, but the Properties command may tell you that it is open.
Some operations and export features require closed polysurfaces, and a model using closed
polysurfaces is generally higher quality than one with small cracks and slivers.
Rhino provides a tool for finding the unjoined or “naked” edges. When a surface is not joined
to another surface, it has naked edges. Use Properties command to examine the object
details. A polysurface that has naked edges lists as an open polysurface. Use the
ShowEdges command to display the unjoined edges.
Other edge tools let you split an edge, merge edges that meet end-to-end, or force surfaces
with naked edges to join. You can rebuild edges based on internal tolerances. Other edge
tools include:
x
x
x
x
SplitEdge splits an edge at a point.
MergeEdge merges edges that meet end to end.
JoinEdge forces unjoined (naked) edges to join nearby surfaces.
RebuildEdges redistributes edge control points based on internal tolerances.
Diagnostics
Diagnostic tools report on an object’s internal data structure and select objects that may
need repair. The output from the List, Check, SelBadObjects, and Audit3dmFile
commands is normally most useful to a Rhino programmer to diagnose problems with
surfaces that are causing errors.
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O R G A N I Z I N G
T H E
M O D E L
Organizing the Model
Rhino offers aids to organizing your work: layers, groups, blocks, and worksessions. Each
method offers a different approach to model organization. Using layers lets you assign a layer
designation to objects. Groups associate objects so they can be selected as one. Blocks let
you store and update an association of objects. Worksessions let you work on a part of a
project while using other models in the project as references.
Layers
Layers are a way of grouping objects and applying certain characteristics to all objects that
have that layer assignment. There are two “mental models” you can use when you think of
layers—layers can be thought of either as a “storage location” for the objects or as a way to
assign a set of characteristics or properties to objects.
Layer states include a layer name, the color used to display the objects, and the on/off and
locked/unlocked status of all the objects on a layer. Objects on layers that are off are not
visible in the model. Objects on locked layers cannot be selected but can be snapped to.
Objects are always created on the current layer. This layer assignment can be changed later.
To accomplish the most common tasks related to layers, click the Layer pane in the status
bar to display the popup layer list. You can set the current layer; change the on/off,
locked/unlocked state; and the layer color. In addition, right-click the layer name to create a
new layer, rename a layer, delete the selected layer, select objects on the selected layer,
change objects to the selected layer, and copy objects to the selected layer.
Accomplish more detailed layer management with the Layers window. Right-click the Layer
pane to open the Layers window. The Layers window sets the current layer, locks and
unlocks layers, turns layers on and off, changes the layer color and sets the layer render
material. You can create new layers, delete layers, move layers up or down in the layer list,
filter the layer list, set the current layer to match an object in the model, change objects to a
selected layer, select all layers, and invert the selection.
The SelLayer command selects all objects on a layer.
Groups
A group is a collection of objects that select as one for moving, copying, rotating, or other
transforms and applying properties such as object color. Grouping objects assigns a group
name to each object that is displayed as a part of its properties. Objects with the same group
name belong to the same group.
x
x
x
x
x
Group groups objects for selection. A group can contain one or more sub-groups.
Ungroup destroys the group.
SetGroupName changes the name assigned by default. Naming different groups to
the same name combines those groups into one.
AddToGroup and RemoveFromGroup add and remove objects from groups.
SelGroup selects groups by name.
Blocks
A block is another way of associating objects together to form a single object. The Block
command creates a block definition in the current model. The Insert command places
instances of this block definition in your model. You can scale, copy, rotate, array, and
otherwise transform block instances in the model. If you redefine the block definition, all
instances of the block are changed to this new definition. Blocks can streamline modeling,
reduce model size, and promote standardization of parts and details.
Multiple instances of block can be located, scaled, and rotated into a model with the Insert
command. Block definitions are created with the Block or Insert command. Materials and
other object properties on block instances are determined by the component objects.
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O R G A N I Z I N G
T H E
M O D E L
Exploding a block instance places the block geometry using the instance location, scale, and
rotation. To redefine a block, use the Explode command to return the block instance to its
original geometry, edit the geometry, and define the block again with the Block command
using the same block name.
The BlockManager command displays a dialog box that lists all the block definitions in the
model. Use the Block Manager dialog box to view block properties, export a block definition
to a file, delete a block definition and all its instances, update a block definition from a file,
find out what blocks are nested in other blocks, and count the number of block instances in
the model.
Worksessions
The Worksession command lets many users work on a large project by managing many
files. Each user can edit a different file in the project and at the same time see the related
portions of the project. By refreshing as needed, each user can see the current version of the
related files in the projects. Only one user can have a file open for editing, but many users
can see it.
Rhino worksessions let you “attach” external files to your current work environment. Attached
geometry cannot be edited (move, scale), but it can be used for input to creation commands
(copy, extrude).
24
A N N O T A T I O N
Annotation
Rhino provides the ability to add notation to your model in the form of dimensions, leaders,
and text blocks. These appear as objects in the model. A different form of notation, the
annotation dots and arrowheads, always display facing towards the view plane.
In addition, you can add notes to the model. Notes do not appear in the model, but display in
a separate window.
Dimensions
You can dimension objects in your model, with your choice of font, units display, decimal
precision, text and arrow size, and text alignment. After dimensions are placed, you can
select all dimensions, edit dimension text, turn control points on to move dimension
elements, and delete dimensions. You can place horizontal, vertical, aligned, rotated, radial,
diameter, and angle, text blocks, leaders, and create a 2-D hidden line drawing.
Dimensions are not associative. Changing your geometry will not update the dimension;
likewise, changing the dimension will not update your geometry.
The Dim command places horizontal and
vertical dimensions depending on the
direction you pick the points.
Dimensions are created using the current
dimension style. Create new dimension styles
to control text size and font, and other
dimension properties. Use the settings in the
Document Properties dialog box to create
new styles and set the properties of existing
styles.
Text
The Text command places annotation text in
your model.
Leaders
The Leader command draws an arrow
leader.
25
A N N O T A T I O N
Annotation Dots
The Dot command places a text dot.
Dots are always parallel to the view. There
are no controls for the dot size. Dots are
displayed in the layer color. Dot size is
constant on the screen. As you zoom in and
out, the dot displays the same size.
Hidden Line Removal
The Make2D command creates curves from the
selected objects as silhouettes relative to the
active view. The silhouette curves are projected
flat and then placed on the world x,y-plane.
The command options create the 2-D drawing
from the current view, current construction
plane, create a four-view layout using US or
European projection angles, set layers for the
hidden lines, and display tangent edges.
Notes
The Notes command provides a means of
storing text information in your model file.
You can type information directly into the
Notes text box. If you leave the Notes box
displayed when you close the model file, it
will display the next time the file is opened.
26
R E N D E R
Render
In addition to shaded previews, Rhino provides
full-color rendering with lights, transparency,
shadows, textures, and bump mapping. If you
want to create photo-realistic renderings, use a
full-featured rendering program, such as
Flamingo.
Objects will render white until you add render
color, highlight, texture, transparency, and
bumps. These attributes are controlled through
the Properties window, Material page.
Lights
In every Rhino rendering there are light sources that Rhino uses to calculate how the objects
are to be illuminated. If you do not add any light sources to your scene, the default light is
used. The default light is a directional light with parallel rays that acts as though you have a
lamp shining over your left shoulder.
Render Mesh
When you shade or render your model, Rhino automatically generates a polygon mesh for
each surface. These meshes are not visible in wireframe view mode, but are only used for
rendering and shading. These meshes are saved and will be used the next time you render
unless you change the model. This makes rendering much faster after the first time.
Render meshes can considerably increase the size of your model file. If you would like to
save file space, the Save Small checkbox on the Save dialog box delete the saved mesh
from the model.
Jagged Objects
A possible problem with rendering is jagged-looking objects that should be smooth. This is
because Rhino generates polygon meshes from all NURBS objects into before rendering.
Depending on the shape of the objects, the default mesh settings may not create enough
polygons, which can make the individual polygons distinguishable, and since the polygons are
flat, they look jagged.
In the Document Properties dialog box, on the Mesh page, under Render mesh quality
click Smooth & slower, or you can use a Custom option.
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T U T O R I A L :
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Tutorial: Solids and Transforms
This tutorial demonstrates using solid
primitives and simple transforms.
You will learn how to:
x
Enter coordinates to place points
exactly.
Draw a free-form curve and polygon.
Create a pipe along a curve.
Use a polar array to copy objects in a
circular pattern.
Extrude a curve to create a surface.
Use planar mode.
x
x
x
x
x
Enter Coordinates
When you pick a point with the mouse, the point lies on the construction plane of the active
viewport unless you use a modeling aid such as object snap or elevator mode. When Rhino
prompts for a point, you can enter x-, y-, and z-coordinates instead of picking a point. Each
viewport has its own construction plane on which its x- and y-coordinates lie. The
z-coordinate for the active viewport is perpendicular to the x-y plane.
The grid is a visual representation of the construction plane. The intersection of the dark red
and green lines shows the location of the origin point (x=0, y=0, z=0) of the coordinate
system.
Draw the Pull Toy Body
This exercise uses x-, y-, and z-coordinates to accurately place points. When you are to type
coordinates, type them just as they are shown in the manual. The format is x,y,z. For
example, type 1,1,4. You must type the commas. This sets the point at x=1, y=1, and z=4
in the active viewport.
Whenever you type points, look in all viewports at where the point is placed so you can start
getting an idea of how coordinate entry works.
Note
Pay close attention to the viewport required in each instruction.
Start the model
1
Begin a new model.
2
In the Template File dialog box, select Small Objects - Centimeters.3dm, and
click Open.
Draw an ellipsoid
1
Turn on Ortho.
2
From the Solid menu, click Ellipsoid > From Center.
3
With the Top viewport active, at the Ellipsoid center… prompt, type 0,0,11 and
press Enter.
This places the center point of the ellipsoid at x=0, y=0, and z=11. Look at the point
in the perspective viewport.
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T U T O R I A L :
4
At the End of first axis… prompt,
type 15 and press Enter.
5
Move the cursor to the right to show
the direction and click.
6
At the End of second axis prompt,
type 8 and press Enter.
7
Move the cursor up to show the
direction and click.
S O L I D S
A N D
T R A N S F O R M S
This sets the width of the ellipsoid.
8
At the Pick point prompt, type 9 and
press Enter.
You now have an egg shape that has
different dimensions in all three
directions.
Rotate the perspective viewport so you
are looking along the x-axis as
illustrated.
Turn on Shaded Viewport display in
the Perspective viewport.
Draw the Axles and Wheel Hubs
The axles and wheel hubs are cylinders. The axles are long, thin cylinders, and the wheel
hubs are short, fat cylinders. You are going to make one axle and one complete wheel. You
will then mirror the complete wheel to the other side. You can then either mirror or copy the
complete axle and wheel set to the front of the toy.
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Create the axle
1
From the Solid menu, click Cylinder.
2
With the Front viewport active, at the
Base of cylinder… prompt, type
9,6.5,10 and press Enter.
3
At the Radius… prompt, type .5 and
press Enter.
4
At the End of cylinder prompt, type 20 and press Enter.
Create a wheel hub
1
From the Solid menu, click Cylinder.
2
With the Front viewport active, at the Base of cylinder… prompt, type 9,6.5,10
and press Enter.
3
At the Radius… prompt, type 4 and press Enter.
4
At the End of cylinder prompt, type 2, and press Enter.
Draw the Lug Nuts
You will make the lug nuts by extruding a hexagonal polygon curve.
Create a hexagon
1
From the Curve menu, click Polygon > Center, Radius.
2
At the Center of inscribed polygon ( NumSides=4…) prompt, type 6 and press
Enter.
3
In the Front viewport, at the Center of inscribed polygon… prompt, type 9,8,12
and press Enter.
This will place the polygon right on the surface of the wheel hub.
4
At the Corner of polygon… prompt, type .5 and press Enter.
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T U T O R I A L :
5
S O L I D S
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In the Front viewport drag the cursor as
illustrated, and click to position the
hexagon.
Make a solid from the polygon
1
Select the hexagon you just created.
2
From the Solid menu, click Extrude Planar Curve > Straight.
3
At the Extrusion distance (Direction BothSides=No Cap=Yes Mode=Straight)
prompt, notice the command options.
Many commands have options. You will learn how to change and use them as you
learn to use the commands. Take a moment and look at the options available for the
ExtrudeCrv command.
Press F1 to look at the Help topic for this command. The Help topic explains the
options.
4
At the Extrusion Distance… prompt,
type -.5 and press Enter.
Notice the negative number. If you type
a positive number at this point, the nuts
will be buried in the wheel hub. You want
them to stick out.
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Assign Colors
Now that you have the basic parts built, you are going to assign colors to them before we
start copying them. If we wait until we have all the parts, you will have to select 20 lug nuts
separately. If we assign colors now, the color property will be copied when we copy the parts.
Assign color to the parts
1
Select the lug nut.
2
From the Edit menu, click Object Properties.
3
In the Properties window, switch to Material
properties.
4
In the Properties window, on the Material
page, under Assign by, click Basic, and then
click the color swatch.
5
In the Select Color dialog box, under Named Colors, click Black, and then click
OK.
6
Select the toy body and repeat steps 4
through 6.
You will be assigning colors to objects as
we go along.
7
Render the Perspective viewport.
Array the Lug Nuts
To create the lug nuts on the first wheel, you are going to use a polar (circular) array. An
array is a set of copies of an object. You control how the copies are made. A polar array
copies the objects around a central point. The objects are rotated as they are copied.
Array the nuts
1
Select the lug nut.
2
From the Transform menu, click Array, and then click Polar.
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T R A N S F O R M S
The hexagon curve is still there, so be sure you select the extruded lug nut. (The
selection menu will list it as a polysurface.)
3
With the Front viewport active, at the
Center of polar array prompt, use the
Cen object snap to snap to the center of
the hub.
4
At the Number of elements… prompt,
type 5 and press Enter.
5
At the Angle to fill <360> prompt,
press Enter.
Draw the Tires
The tires are a solid form called a torus, which looks like a donut. When you are drawing a
torus, the first radius is the radius of a circle around which the “tube” is drawn. The second
radius is the radius of the tube itself.
To draw the tires, you will draw the center of the torus tube a bit larger than the diameter of
the wheel hub. The tube itself is slightly larger than the hub. This makes it dip into the hub.
Create a torus for the tires
1
From the Solid menu, click Torus.
2
In the Front viewport, at the Center of torus… prompt, type 9,6.5,11 and press
Enter.
This places the center of the torus at the same point as the center of the wheel hub.
3
At the Radius… prompt, type 5 and
press Enter.
This makes the center of the torus tube
one unit larger than the wheel hub.
4
At the Second radius… prompt, type
1.5 and press Enter.
This makes the hole .5 units smaller than
the wheel hub.
5
Set the Color of the tire to Black and
the Gloss finish to about 40.
6
Render the Perspective viewport.
Mirror the Wheels
Now that you have a whole wheel created, you can use the Mirror command to create the
other three.
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Mirror the wheel to the other side
1
In the Top viewport, use a window to
select the wheel as illustrated.
2
From the Transform menu, click
Mirror.
3
At the Start of mirror plane… prompt,
type 0,0,0 and press Enter.
4
At the End of mirror plane… prompt,
with Ortho on, drag to the right in the
Top viewport as illustrated and click.
Mirror the front wheels and axle
1
In the Top viewport, use a window to
select the wheels and axle as illustrated.
2
From the Transform menu, click
Mirror.
3
At the Start of mirror plane… prompt,
type 0,0,0 and press Enter.
4
At the End of mirror plane… prompt,
with Ortho on, drag down in the Top
viewport as illustrated and click.
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Draw the Eyes
You are going to draw a sphere for an eye and a smaller sphere for the pupil.
Create an eye
1
From the Solid menu, click Sphere, and then click Center, Radius.
2
At the Center of sphere… prompt, in
the Top viewport, type -12,-3,14 and
press Enter.
3
At the Radius… prompt, type 3 and
press Enter.
4
Repeat the Sphere command.
5
At the Center of sphere… prompt, in
the Top viewport, type -13,-4,15 and
press Enter.
6
At the Radius… prompt, type 2 and
press Enter.
7
Change the color of the pupil to black.
Mirror the eye
1
In the Top viewport, use a window to
select the eye as illustrated.
2
From the Transform menu, click
Mirror.
3
At the Start of mirror plane… prompt,
type 0,0,0 and press Enter.
4
At the End of mirror plane… prompt,
with Ortho on, drag to the left in the
Top viewport as illustrated and click.
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T U T O R I A L :
5
Right-click the Perspective viewport
title.
6
From the Viewport title menu, click
Rendered.
S O L I D S
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T R A N S F O R M S
Make the Pull Cord
To make the cord, you are going to draw a freehand curve using elevator and planar mode.
When the curve is complete, use the Pipe command to make it a thick solid.
Create the pull cord at the front of the toy
1
Zoom out in all the viewports; you are going to need some space to work.
2
On the status bar, turn Planar mode on,
and turn Ortho off.
3
In the Osnap dialog box, click Disable
to turn off all object snaps.
4
From the Curve menu, click Free-form,
and then click Control Points.
5
At the Start of curve… prompt, in the
Top viewport, hold Ctrl to activate
elevator mode and click near the front
end of the ellipsoid.
6
Move the cursor to the Front viewport,
drag the marker near the end of the
ellipsoid, and click.
7
At the Next point… prompt, click to the
left of the ellipsoid in the Top viewport.
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Planar mode keeps successive points at
the same construction plane elevation.
Planar mode can be overridden with
elevator mode or object snaps. Watch
the curve in the Top and Front
viewports.
8
At the Next point… prompt, use
elevator mode to add another point in
the Top viewport.
9
At Next point… prompts, turn off
Planar mode and click several more
points in the Top viewport to create a
curved line.
Notice that the points are projected to
the Top construction plane.
10 Draw an Ellipsoid to represent a handle
at the end of the curve.
In the Osnap dialog box, clear the
Disable checkbox and use the End
object snap to snap the ellipsoid to the
end of the curve
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Make the cord fat
1
Select the curve you just made at the
front of the pull toy.
2
From the Solid menu, click Pipe.
3
At the Start radius… prompt, type .2
and press Enter.
4
At the End radius… prompt, press
Enter.
5
At the Point for next radius prompt,
press Enter.
The pipe will be the same diameter for
the full length of the curve.
6
Set Materials for the objects.
7
Render the Perspective viewport.
38
T U T O R I A L :
R E V O L V E
C U R V E S
Tutorial: Revolve Curves
Drawing objects using solid primitives, as you
have done in the previous exercises, limits the
shapes you can create. Creating surfaces from
curves and joining the surfaces together allows
you much greater freedom.
This tutorial introduces the concept of drawing
curves and one method of creating surfaces from
those curves. This exercise creates a revolved
surface from a profile curve. Revolving curves is
a good method for creating tubular shapes like
vases, wineglasses, and chair legs.
You will learn how to:
x
x
x
x
Draw free-form curves based on an existing object.
Edit control points.
Revolve surfaces around an axis.
Assign properties and render.
Create a Free-Form Flashlight Model
If you have not already done so, work through the “Flashlight” tutorial you will find in the
Rhino Help, Getting Started Tutorials. This tutorial emphasizes using solid polysurfaces and
Booleans to create a mechanical shape. To try this tutorial, from the Rhino Help table of
contents, click Getting Started, and then click the Flashlight link.
You are going to use the flashlight from that tutorial as a guide for drawing the curves you
will need for the new model. Using the old flashlight gives you a frame of reference for
deciding about the size and shape of the object. If you did not work through this tutorial or
save your model, a completed model is provided.
To get started
1
On the Rhino Help menu, click Learn Rhino, and then click Open Tutorial Models.
2
Open the model file Flashlight.3dm.
Set Up the Model
You are going to trace around the old flashlight. To make this easier, you will lock the
objects. When objects are locked, you can see them and snap to them, but you cannot select
them. This keeps the objects from interfering when you want to select things close by. You
can still use object snaps to snap to locked objects. You will then create some curves and
revolve them to make the new flashlight.
Lock the flashlight objects
1
Select all the objects.
Press Ctrl + A to select all the objects in
the model.
2
From the Edit menu, click Visibility,
and then click Lock.
39
T U T O R I A L :
R E V O L V E
C U R V E S
Draw a Centerline
Draw a construction centerline through the center of the old flashlight.
Draw the construction centerline
1
From the Curve menu, click Line, and
then click Single Line.
2
At the Start of line… prompt, use the
Center object snap to place the start of
the line at the center of the flashlight
base.
3
At the End of line… prompt, turn Ortho
on, and draw the line through the exact
center of the old flashlight.
Draw the Body Profile Curve
You are going to draw a profile curve that you will use to revolve to create the flashlight
body. A profile curve defines a cross-section of one half of the part.
Draw the body curve
1
On the status bar, click the Layer pane
and make the layer Free Form Body
current.
2
From the Curve menu, click Free-Form,
and then click Control Points.
3
At the Start of curve… prompt, in the
Front viewport, start drawing a curve
around the flashlight body as illustrated.
Use the End object snap to start the
curve at the end of the construction
centerline.
Use the Near object snap to end the
curve on the construction centerline.
Starting and ending the curve exactly on
the line is important so that later when
you revolve the curve to create a solid,
there will be no gaps or overlapping
parts.
When drawing the curve, use Ortho to
control the first two points on the curve.
If the first two points and the last two
points are placed in a straight line, the
curve will start and end tangent to that
line.
40
T U T O R I A L :
4
R E V O L V E
C U R V E S
When you have placed the last control point, press Enter to finish drawing the curve.
To place the last two points in a straight line with each other, use grid snap, Ortho,
or Perp object snap.
Draw the Lens Profile Curve
Make another profile curve for the lens.
Create the lens
1
From the Curve menu, click Free-Form,
and then click Control Points.
2
At the Start of curve… prompt, in the
Front viewport, place the first control
point of the lens profile.
Use the Near object snap to start and
end the curve on the construction
centerline.
Place control points in the upper part of
the lens curve so it crosses the body
profile curve.
Get the old flashlight out of your way
1
From the Edit menu, click Visibility,
and then click Unlock.
2
Select all the objects except the two
profile curves you just drew and the
switch sphere.
3
From the Edit menu, click Visibility,
and then click Hide.
Build the Flashlight Body
To make the body, you will revolve the profile curve 360 degrees. You will use the endpoint
of the curve and ortho to establish the rotation axis.
Create the flashlight body
1
From the Surface menu, click Revolve.
2
At the Select curve to revolve prompt,
select the body profile curve.
3
At the Start of revolve axis prompt,
snap to one endpoint of the body curve.
4
At the End of revolve axis prompt, turn
Ortho on, and specify the revolve axis
line as illustrated.
41
T U T O R I A L :
5
R E V O L V E
C U R V E S
In the Start angle... prompt, click the
FullCircle option.
Create the Lens
Now revolve the lens profile curve in the same way as the body.
Revolve the lens profile curve
1
From the Surface menu, click Revolve.
2
At the Select curve to revolve prompt,
select the lens profile curve.
3
At the Start of revolve axis prompt,
use End object snap to locate the
endpoint of one of the curve profiles.
4
At the End of revolve axis prompt, turn
Ortho on, and draw the revolve axis line
as illustrated.
5
In the Start angle... prompt, click the
FullCircle option.
Assign Properties and Render
Assign object properties to the body and lens and render. In illustration, the body is red with
a small highlight; the lens is about 50% transparent.
42
T U T O R I A L :
R E V O L V E
C U R V E S
Assign object properties and render
1
Draw a Plane under the flashlight to
provide an object to receive shadows.
2
From the Edit menu, click Object
Properties, and select the Material
window.
3
Set the properties for each of the
flashlight parts.
4
Render the Perspective viewport.
43
T U T O R I A L :
S W E E P ,
L O F T ,
A N D
E X T R U D E
Tutorial: Sweep, Loft, and Extrude
This tutorial demonstrates creating surfaces
from profile curves using lofts, sweeps, and
extrudes.
You will learn how to:
x
x
Create a surface from a planar curve.
Loft, revolve, sweep, and extrude
surfaces.
Cap planar holes to create a solid.
Create solid pipes.
Mirror objects.
Use layers.
Use object snaps.
x
x
x
x
x
A model is provided as a starting point. If you have not completed the Getting Started
tutorials in the Rhino Help, try them first.
To open the headphone model
1
On the Rhino Help menu, click Learn Rhino, and then click Open Tutorial Models.
2
Open the model file Headphone.3dm.
Create the Speaker Shell
The speaker shell is created using a lofted surface, a one-rail sweep, a solid extrusion of a
planar curve, and a surface fillet. The resulting geometry is joined into one solid.
Loft Curves to Create a Surface
One way to create a surface is to use existing curves as a guide. When you loft through
curves, the curves are used as a guide for creating a smooth surface.
Make a surface by lofting curves
1
Turn on ShadedViewport in the
Perspective viewport.
2
Select the three circular curves, with a
crossing selection as illustrated.
3
From the Surface menu, click Loft.
4
At the Adjust curve seams… prompt,
note the display of the curve direction
arrows at the seam points, and press
Enter
In this model, they are nicely lined up for
you, so you do not need to adjust them.
44
T U T O R I A L :
5
S W E E P ,
L O F T ,
A N D
E X T R U D E
In the Loft Options dialog box, click OK
to create the loft.
Extrude a Curve into a Solid
You are going to extrude the curve in the center to make a magnet housing.
To make a solid cylinder by extruding a circular curve
1
Select the curve at the center of the
lofted surface.
2
From the Solid menu, click Extrude
Planar Curve > Straight.
3
At the Extrusion Distance… prompt,
type -2 and press Enter.
This makes a solid cylinder for the
magnet housing that is two units thick
and extends in the negative direction
from the original curve.
Zoom in on the cylinder
1
Select the cylinder.
2
From the View menu, click Zoom, and
then click Zoom Selected.
The cylinder you just created is a closed
polysurface (solid) consisting of three
joined surfaces—the side, top, and
bottom. To remove the bottom, extract
the face.
3
From the Solid menu, click Extract
Surface.
45
T U T O R I A L :
4
At the Select surfaces to extract…
prompt, select the surface as illustrated
and press Enter.
5
Press the Delete key.
S W E E P ,
L O F T ,
A N D
E X T R U D E
Fillet the edge of the cylinder surface
1
From the Solid menu, click Fillet
Edge > Fillet Edge.
The current radius setting should be 1.
2
At the Select edges to fillet…
prompt, select the edge at the top of
the cylinder press Enter.
3
At the Select fillet handle to edit
prompt, press Enter.
46
T U T O R I A L :
S W E E P ,
L O F T ,
A N D
E X T R U D E
Join the Surfaces Together
Surfaces that share an edge can be joined into a polysurface. You will join all the surfaces.
Since the faces are sometimes hard to see, use two viewports to select them all.
To join the surfaces
1
Select the surface and the polysurface.
2
From the Edit menu, click Join.
To join surfaces, you must select
surfaces that are adjacent to each other
and the edges must match.
Create the Padding
To create the padding around the edge of the speaker you will sweep a curve around the
edge of the speaker cone.
Sweep a curve along one rail
1
From the View menu, click Zoom, and
then click Zoom Extents All.
2
Select the curves as illustrated.
3
From the Surface menu, click Sweep 1
Rail.
4
In the Sweep 1 Rail Options dialog
box, click OK.
47
T U T O R I A L :
S W E E P ,
L O F T ,
A N D
E X T R U D E
Create the Speaker Cone Cover
You are going to fill the area at the base of the padding with a planar surface created from
the edge of the sweep.
Make a surface from planar curves
1
From the Surface menu, click From
Planar Curves.
2
Select the curve on the edge of the
speaker cone as illustrated.
A planar surface is created at the base of
the padding.
Create the Mounting Bracket
The next part is the bracket that holds the speaker to the headband. Since the speaker unit is
complete, you can turn its layer off and make the Bracket layer current.
To reset the layers and view
1
On the status bar, click the Layer pane.
2
Make Bracket the current layer and turn on Bracket Shape Curves.
Turn all other layers off.
3
From the View menu, click Zoom, and then click Zoom Extents All to zoom in on
the bracket shape curves in all viewports.
Create a Solid by Extruding a Curve
You can use a planar curve to create a solid shape
48
T U T O R I A L :
S W E E P ,
L O F T ,
A N D
E X T R U D E
To extrude a curve into a solid
1
Select the closed curve.
2
From the Solid menu, click Extrude
Planar Curve > Straight.
3
At the Extrusion distance… prompt,
type -1 and press Enter.
Fillet the Edges to Smooth Them
You can round the sharp edges with a fillet.
Fillet the edges
1
From the Solid menu, click Fillet Edge
> Fillet Edge.
2
At the Select edges to fillet… prompt,
type .2 and press Enter.
3
At the Select edges to fillet… prompt,
select both edges and press Enter.
4
At the Select fillet handle to edit
prompt, press Enter.
49
T U T O R I A L :
S W E E P ,
L O F T ,
A N D
E X T R U D E
Create the Mounting Pins
You can create the mounting pins with the Pipe command.
To create a tubular surfaces from the shape curves
1
Select the curve at the top of the
bracket.
2
From the Solid menu, click Pipe.
3
At the Starting radius… prompt, type
.3 and press Enter.
Before typing the radius, make sure the
options are set to Cap=Flat and
Thick=No.
4
At the End radius… prompt, press
Enter.
5
At the Point for next radius prompt,
press Enter.
6
Select the curve at the bottom of the
bracket.
7
From the Solid menu, click Pipe.
8
At the Starting radius… prompt, type
.2 and press Enter.
9
At the End radius… prompt, press
Enter.
10 At the Point for next radius prompt,
press Enter.
Create the Headband
The headband consists of a series of ellipses swept along a path.
Reset the layers and view
1
On the status bar, click the Layer pane.
2
Make Headband the current layer and turn on Headband Shape Curves.
Turn all other layers off.
3
From the View menu, click Zoom, and then click Zoom Extents All to zoom in on
the headband shape curves in all viewports.
50
T U T O R I A L :
S W E E P ,
L O F T ,
A N D
E X T R U D E
Create an ellipse perpendicular to a curve
1
Turn Ortho on.
2
From the Curve menu, click Ellipse, and
then click From Center.
3
At the Ellipse center… prompt, click
AroundCurve.
4
At the Ellipse center prompt, snap to
an endpoint of the headband curve.
Use the End object snap.
5
At the End of first axis prompt, type
0.5 and press Enter.
6
At the End of first axis prompt, drag
the cursor in the x-direction and click.
7
At the End of second axis prompt,
type 2, and press Enter.
8
At the End of second axis prompt, drag
the cursor in the y-direction and click.
Array a curve along a path
1
Select the ellipse.
2
From the Transform menu, click Array,
and then click Along Curve.
3
At the Select path curve prompt, select
headband curve.
51
T U T O R I A L :
4
In the Array Along Curve Options
dialog box, under Method, set the
Number of items to 3.
5
Under Orientation, click Freeform and
click OK.
S W E E P ,
L O F T ,
A N D
E X T R U D E
Scale the Ellipse
In the next step, scale the center ellipse to make it larger.
Scale the ellipse
1
Select the center ellipse.
2
From the Transform menu, click Scale,
and then click Scale1-D.
Scale1D stretches an object in one
direction.
3
At the Origin point… prompt, in the
Perspective viewport, snap to the
center of selected ellipse.
4
At the Scale factor or first reference
point… prompt, type 2, and press
Enter.
5
At the Second reference point… prompt, drag the cursor in the y-direction and
click.
Sweep along one rail
1
From the View menu, click Zoom, and
then click Extents All.
2
Select the curves.
3
From the Surface menu, click Sweep 1
Rail.
52
T U T O R I A L :
4
At the Adjust curve seams… prompt,
examine the direction and seam points of
the curves to make sure they are not
twisted, and press Enter.
5
In the Sweep 1 Rail Options dialog
box, click OK.
S W E E P ,
L O F T ,
A N D
E X T R U D E
Create a Rounded Shape at the Ends of the Headband
Using the same ellipse that formed the first cross-section curve for the headband, create a
rounded end for the headband. To create the surface that will be joined to the headband, split
the ellipse in half.
Split the ellipse in half
1
From the View menu, click Zoom, and
then click Window.
2
In the Perspective viewport, zoom in on
the left end of the headband you just
created.
3
Turn on Quad object snap.
4
Select the ellipse.
5
From the Edit menu, click Split.
6
At the Select cutting objects…
prompt, type P, and press Enter.
7
At the Point to split curve prompts,
snap to the two quadrants at the narrow
axis of the ellipse.
8
At the Point to split curve prompt,
press Enter.
The ellipse is split into two halves.
Create a surface of revolution
1
Select left half of the ellipse.
2
From the Surface menu, click Revolve.
53
T U T O R I A L :
3
At the Start of revolve axis prompt,
snap to the end of the ellipse half.
4
At the End of revolve axis prompt,
snap to the other end of the ellipse half.
5
At the Start angle... prompt, type 0,
press Enter.
6
At the Revolution angle... prompt, type
180, press Enter.
S W E E P ,
L O F T ,
A N D
E X T R U D E
A rounded surface is created at the end
of the headband.
7
Repeat these steps for the other side of the headband.
Join the surfaces
1
Select the surfaces.
2
From the Edit menu, click Join.
Three surfaces joined into one
polysurface.
Create the Speaker Wire
Use a separate layer to create the speaker wire.
Reset the layers and view
1
On the status bar, click the Layer pane.
2
Make Wire Shape Curves the current layer and turn on Wire.
Turn all other layers off.
3
From the View menu, click Zoom, and then click Zoom Extents All to zoom in on
the wire shape curves in all viewports.
Make the helix
1
From the Curve menu, click Helix.
2
At the Start of axis… prompt, click
AroundCurve.
3
At the Select curve prompt, select the
long free-form curve.
54
T U T O R I A L :
4
S W E E P ,
L O F T ,
A N D
E X T R U D E
At the Radius and start point…
prompt, type 1 and press Enter.
This sets the radius for the helix.
5
At the Radius and start point…
prompt, set Turns=30, and
NumPointsPerTurn=8.
6
At the Radius and start point…
prompt, in the Right viewport drag the
cursor to the left and click.
Match and join the helix to the end curves
1
From the View menu, click Zoom, and
then click Window.
2
In the Perspective viewport, zoom in on
the left end of the helix you just created.
3
From the Curve menu, click Curve Edit
Tools, and then click Match.
4
At the Select open curve to change - pick near end prompt, select near the left
end of the helix.
5
At the Select open curve to match - pick near end… prompt, select near the
lower end of the vertical curve.
6
In the Match Curve dialog box, under Continuity, click Tangency, under Preserve
other end, click Position, and click Join.
7
Repeat steps 3 through 6 for the other end of the helix.
Create the speaker wire
1
Select the extended helical curve.
2
From the Solid menu, click Pipe.
3
At the Starting radius… prompt, type
.2 and press Enter.
4
At the End radius… prompt, press
Enter.
5
At the Point for next radius prompt,
press Enter.
55
T U T O R I A L :
6
Select the curve at the top left.
7
From the Solid menu, click Pipe.
8
At the Starting radius… prompt, type
0.1 and press Enter.
9
At the End radius… prompt, press
Enter.
S W E E P ,
L O F T ,
A N D
E X T R U D E
10 At the Point for next radius prompt,
press Enter.
Mirror the Headphone Parts
To create the parts for the other side of the headphones, mirror the parts you have already
created.
Reset the layers and view
1
On the status bar, click the Layer pane.
2
Turn on all layers.
3
From the View menu, click Zoom, and then click Zoom Extents All.
Delete all the shape curves
1
Press Esc to deselect everything.
2
From the Edit menu, click Select Objects, and then click Curves.
3
Press the Delete key.
Mirror the left half of the headphones
1
In the Front viewport, window select the
objects as illustrated.
(Select the speaker, bracket, small wire,
and rotated ellipse.)
2
From the Transform menu, click
Mirror.
The Mirror command depends on which
viewport is active. It uses the
construction plane in the active viewport
to define the mirror plane. The mirror
plane is perpendicular to the construction
plane. Two points define the line in this
plane about which the selected objects
are mirrored.
3
At the Start of mirror plane prompt,
type 0,0.
This is the first point of the mirror line.
56
T U T O R I A L :
4
S W E E P ,
L O F T ,
A N D
E X T R U D E
At the End of mirror plane prompt, turn on Ortho, and drag the mirror line straight
up and pick.
Complete the headphone model
`
Add materials to the headphones and
render.
57
T U T O R I A L :
P O I N T
E D I T I N G
A N D
B L E N D
S U R F A C E S
Tutorial: Point Editing and Blend Surfaces
This tutorial demonstrates point-editing
techniques including moving and scaling control
points and adding knots to surfaces to increase
control. In addition, you will use blends to create
smooth transitions between surfaces.
You will learn how to:
x
Rebuild surfaces to add additional control
points.
Insert knots in a surface to add control
points in a specific location.
Edit surface control points to define a
shape.
Scale control points to change the object
shape.
Use object snaps projected to the
construction plane.
Orient an object on a surface.
Create smooth blends between surfaces.
x
x
x
x
x
x
Rendered with Penguin renderer by Jari
Saarinen.
If you have not completed the Rubber Duck tutorial in the online Rhino Getting Started, try it
first. To view the online tutorial, from the Rhino Help menu table of contents, click Getting
Started.
Create the Body and Head
If you like, open the example model, Penguin.3dm, and try to match the shapes as you are
building the model. Experiment with your own shapes, too.
The body and head are created from one sphere. The shape is formed by moving the control
points in the sphere to create the head.
Create the body
1
In the Top viewport, use the Sphere
command to draw a sphere with a radius
of 10 units.
2
Use the Rebuild command to add more
control points to the sphere.
In the Rebuild Surface dialog box, set
the Point count in the U and V
directions to 8 and the Degree in the U
and V directions to 3.
Check Delete input.
Click OK.
58
T U T O R I A L :
3
P O I N T
E D I T I N G
A N D
B L E N D
S U R F A C E S
Use the PointsOn command to turn on
the sphere’s control points. Look in all
the viewports at the structure of the
control points.
The next step will change this structure
so the influence of moving the control
points does not extend over the whole
sphere.
4
Use the InsertKnot command to insert
two knots in the sphere in the area
where you want the neck.
Insert the knots in the u-direction only
as illustrated.
5
Examine the control point structure after
inserting the knot.
6
Reposition control points to create the indentation for the neck and to reform the
body shape.
You might try the following operations:
7
Use the SetPt command to create a flat
bottom. In the Front viewport, select all
the control points in the lowest rows of
the sphere and set them to match the
bottom pole point in the world z-direction
only.
In the Set Points dialog box, check Set
Z, clear the Set X and Set Y
checkboxes, and click World.
Drag the selected control points up.
59
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This will align all of the selected control
points to the same z-value (up in Front
viewport), flattening the surface.
8
Select rows of control points with a
window and drag them up or down in the
Front viewport.
Use WireFrameViewport mode if you
find it easier to select control points in
wireframe views.
9
Select rows of control points with a
window in the Front viewport. In the
Top viewport, use the Scale2D
command to move them closer or farther
away from the central point.
To pick the base point for the Scale2D
command use the Point object snap with
Project turned on. This will scale the
points parallel to the construction plane.
Watch the Front viewport to see the
changes in the body shape as you move
the control points closer to and farther
from the center.
60
T U T O R I A L :
P O I N T
E D I T I N G
A N D
B L E N D
S U R F A C E S
Experiment with the Project setting in
the Osnap toolbar to see how it works.
You will be able to see the tracking line
projected to the construction plane in the
viewports.
Match the example model or use your
own shape.
10 Move individual groups of control points
to make the body slightly flatter in the
front near the neck as illustrated.
Create and Place the Eyes
The eye is an ellipsoid shape that is oriented onto the surface.
Create the eye
1
In the Top viewport, start the Ellipsoid
command.
Place the center point anywhere.
2
At the End of first axis prompt, type
1.1 to constrain the distance from the
center point to the end of the axis to 1.1
units.
Drag the cursor to the right and pick.
3
At the End of second axis prompt, type
1.1 to constrain the distance.
Using these constraints has created a
circular ellipsoid when seen from the top.
Drag the cursor up or down in the Top
viewport and pick.
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T U T O R I A L :
4
P O I N T
E D I T I N G
A N D
B L E N D
S U R F A C E S
At the End of third axis prompt, type
.5, press Enter.
Move the eye onto the surface
1
Select the eye ellipsoid in the Top or Perspective viewport.
2
Start the OrientOnSrf command.
3
At the Reference point 1 prompt, in the
Top viewport, pick the center of the
ellipsoid.
4
At the Reference point 2 prompt, pick
any point to the right or left of the eye
ellipsoid.
5
At the Surface to orient on prompt,
select the penguin body/head.
6
In the Orient on Surface dialog box,
uncheck the Copy objects option, click
OK.
7
At the Point on surface to orient to… prompt, move the cursor onto the head to
where you want to place the eye and click.
8
Use the Mirror command in the Front
viewport to create the second eye.
The exact location is not important.
Create the Beak
The beak is another ellipsoid that you can edit to change the shape.
62
T U T O R I A L :
P O I N T
E D I T I N G
A N D
B L E N D
S U R F A C E S
Create the beak shape
1
In the Top viewport, start the Ellipsoid
command.
Place the center point anywhere.
2
At the End of first axis prompt, type 3
to constrain the distance from the center
point to the end of the axis to three
units.
Drag the cursor to the right and pick.
3
At the End of second axis prompt, type
2 to constrain the distance.
Using these constraints creates a circular
ellipsoid when seen from the top.
Drag the cursor up or down in the Top
viewport and pick.
4
At the End of third axis prompt, type
1, press Enter.
5
Turn on the control points (F10).
In the Front viewport, select the lower
row of points and drag them down.
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P O I N T
E D I T I N G
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Select the row of points in the top center
and drag them down to shape the beak.
Try using the Nudge keys (Alt + Arrow
direction keys) to nudge the selected
points.
7
Move the beak into position.
Create the Feet
The feet are created using another ellipsoid. Knots are added to help create the webbed toes.
Draw the beginning ellipsoid
1
In the Front viewport, start the Ellipsoid command.
2
At the End of first axis prompt, type 1 to constrain the distance from the center
point to the end of the axis to one unit.
Place the center point anywhere.
Drag the cursor up and pick.
3
At the End of second axis prompt, type
3 to constrain the distance.
In the Top viewport, drag the cursor up
and pick.
4
At the End of third axis prompt, type
3, press Enter
5
Use the Rebuild command to add more control points to the ellipsoid.
In the Rebuild Surface dialog box, set the Point count in the U and V directions
to 8 and the Degree in the U and V directions to 3.
Check Delete input.
Click OK.
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Create the webbed feet
1
Insert four knots in the ellipsoid as
illustrated.
Set the Symmetrical=On.
Insert the knots in the V-direction.
2
Select control points as illustrated.
Use window and crossing selections to
select the control points on both the top
and bottom of the ellipsoid.
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P O I N T
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Use the Scale2D command to scale the
control points out from the center of the
foot.
Use the Point object snap to set the
base point of the scale to the center
point of the ellipsoid.
Drag the points to make the whole foot
about twice the size of the original
ellipsoid.
Position the feet
1
Use the Move command to move the
foot under the penguin body.
2
Use the Rotate command to rotate the
foot out slightly.
3
Use the Mirror command to create the
second foot.
Flatten the bottoms of the feet
To finish the feet, create a plane through the feet and use a Boolean intersection to
trim the feet, the plane, and join the surfaces in one step.
1
Select the feet.
2
In the Front viewport, use the CutPlane
command to make a planar surface that
passes through the feet as illustrated.
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The CutPlane command makes a plane
that passes through the selected
surfaces along the line you draw.
3
Select the plane and the feet.
4
Start the Boolean2Objects command.
5
Click through the preview options until
the result is the flat feet as illustrated,
and press Enter.
Create the Tail
The tail is another ellipsoid. It is joined to the body with a smooth blend surface.
Create the tail shape
1
Draw an Ellipsoid that is 4 units long, 3
units wide (Top viewport), and 1.5 units
tall (Front viewport).
2
Use the Rotate and Move commands to
place the tail in position.
Attach the tail to the body with a smooth blend
1
Use the BooleanUnion command to trim and join the tail and the body shapes.
The transition between the tail and body is rather abrupt; so replace this with a
smooth blend surface.
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To do this, you must first create a gap between the two parts for the blend surface to
fill.
2
Use the Pipe command to create a
circular surface around the edge between
the body and tail.
At the Select curve to create pipe
around prompt, select the edge
between the tail and the body.
At the Radius for closed pipe prompt,
type .4.
3
Use the BooleanDifference command
to trim both the body and the tail
surfaces inside the pipe.
Use the DeleteInput option to delete
the original surfaces.
4
At the Select first set of surfaces…
prompt, select the body/tail and press
Enter.
5
At the Select second set of surfaces…
prompt, select the pipe surface and
press Enter.
6
Use the Explode command to separate
the parts.
7
Delete the part of the pipe remaining
between the body and tail.
8
Use the BlendSrf command to create a
smooth surface between the tail and the
body.
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Create the Wings
The wing is another ellipsoid shape. Use control point editing to make the wing shape. Start
the ellipsoid in the Top viewport.
Create the wing shape
1
Draw an Ellipsoid that is 2 units long,
2 units wide (Top viewport), and 6.5
units tall (Front viewport).
2
Use the Rebuild command to add more
control points to the ellipsoid.
In the Rebuild Surface dialog box, set
the Point count in the U and V
directions to 8 and the Degree in the U
and V directions to 3.
Check Delete input.
Click OK.
3
Drag control points to create the shape.
4
Use the Bend command in the Front
viewport to bend the top of the wing
shape toward the body.
At the Start of spine prompt, in the
Front viewport, pick near the bottom of
the wing.
At the End of spine prompt, pick near
the top of the wing.
At the Point to bend through…
prompt, drag the top of the wing toward
the body.
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5
If further positioning is needed, use the
Rotate and Move commands to place
the wing.
6
Use the Mirror command to create the
opposite wing.
P O I N T
E D I T I N G
A N D
B L E N D
S U R F A C E S
Attach the wings to the body with a smooth blend
To create the gap between the wings and body to fill with a blend surface, try a
slightly different approach from the tail. Create the pipe and trim the surfaces inside
the pipe.
1
To trim the wing hole and the wing,
select both wings and the body and use
the BooleanUnion command.
2
Use the Explode command to separate
the parts.
3
Use the Pipe command to create a
circular surface around the edge between
the body and each wing.
At the Select curve to create pipe
around prompt, select the edge of the
hole in the body or the edge of the wing
surface.
At the Radius for closed pipe prompt,
use a radius of about .6.
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4
Use the Trim command to trim the body
and wing surfaces inside the pipe
surfaces.
5
Delete the pipe surfaces.
6
Use the BlendSrf command to create a
smooth surface between each wing and
the body.
7
Join the blends and wings to the body
E D I T I N G
A N D
B L E N D
S U R F A C E S
Finishing Touches
To finish the penguin, split the front part of the body so a different material can be applied
to it.
Separate the front part of the body
1
In the Right viewport, draw a curve
from the beak down to the bottom as
illustrated.
2
Use the Split command to split the body
surface with the curve.
3
Use the Join command to join the body
(except the front), the tail, and the
wings.
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Apply Render Materials
Rendering creates a “realistic” picture of your model with colors you assign. These render
colors are different from the layer colors you might be using, which control the display in
wireframe mode.
Render the penguin
1
Select the body.
2
Start the Properties command.
3
In the Properties window, from the list, select Material.
4
Under Assign by, click Basic.
5
Click the color bar.
6
In the Select Color dialog box, select a
color for the body.
7
Set the Gloss finish to about 40.
8
Select the other parts and apply
materials in the same way.
9
Use the RenderedViewport command
to set the viewport rendered mode.
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Tutorial: Loft a Boat Hull
This tutorial demonstrates classic boat hull lofting
techniques using typical plan and profile curves.
The classic hull shape is based a design from an
old Boat Builder’s Handbook magazine. Many
designs similar to this are available over the
Internet.
You will learn how to:
x
x
x
x
Create 3-D curves from a 2-D lines
drawing.
Rebuild and simplify the curves.
Use analytical techniques to ensure
fairness.
Loft surfaces from the curves.
Rhino is used by marine designers in many segments of the industry. For more tutorials and
information about marine design, see the Rhino Web site at www.rhino3d.com.
Marine Terms Used in this Tutorial
Sheer
The fore-and-aft curvature from the bow to the stern of a ship’s deck as shown in side
elevation.
Chine
The intersection of the bottom and the sides of a flat or v-bottomed boat.
Transom
The planking forming the stern of a square-ended boat.
Fair
The meaning of “fair” is much debated in the marine industry. No one can define it, but they
know when they see it. Although fairing a surface is traditionally associated with hull
surfaces, all visible surfaces on any object can benefit from this process. In Rhino, the first
cue for fairness in a surface is the spacing of the surface display isocurves.
There are other characteristics of fair curves and surfaces. Although a curve or surface may
be fair without exhibiting all of the characteristics, they tend to have these characteristics. If
you keep these in mind while modeling, you will end up with a better final product.
The guidelines for creating a fair surface include:
x
x
Use the fewest possible control points to get the curve shape.
Use the fewest possible curves to get the surface shape.
Lay Out the Hull Curves
The hull lines were created by tracing the
original plans using a background bitmap. The
first step is to check the lines for fairness before
creating surfaces from them.
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The designer’s lines are illustrated. The sheer
and chine have been extended at the forward
and aft ends to accommodate the lofting
process.
Start the Model
1
On the Rhino Help menu, click Learn Rhino, and then click Open Tutorial Models.
2
Open the model file Victory.3dm.
The lines are laid out on the Plan layer and the Profile layer.
Check for Fairness
Select each of the designer’s curve pairs in plan and profile and use the CurvatureGraphOn
command to determine if the curves are “fair.” In this case, the file has the original curves
that were traced from the background bitmap. They are not "fair." In other words, the curves
do not smoothly transition from one end of the sheer to the other. If any curve is not fair,
adjust points to make it fair. Start with the sheer (the curve at the top of the hull shape). It
has the biggest impact on the appearance of the vessel.
The illustration shows the curvature graph applied to the two-dimensional sheer in profile.
Check the curves for fairness
1
Select the curves you want to check.
2
Use the CurvatureGraphOn command
to display its curvature graph.
The curvature graph should be continuous and exhibit the characteristics desired for the
curve. When the curve is concave downward, the graph will be above the curve. Conversely,
concave upward curves will have their graphs below them. The point of inflection (where the
curve is neither concave upward nor downward) is indicated where the graph crosses the
curve.
Rebuild the Curves
Before doing any point editing to make the curves fair, rebuild the curves to remove excess
control points.
Select each curve and use the Rebuild command to reduce the number of points and set the
degree. Do not use more points than you absolutely need.
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Use the CurvatureGraphOn command to check the curves again for fairness. If the
curvature graph is still not satisfactory, move the control points until you have a smooth
graph. Proceed with the rest of the curves in the model to be certain they are fair before
beginning to surface the model.
Rebuild the curves
1
Select the sheer curve.
2
Start the Rebuild command.
3
In the Rebuild Curve dialog box,
change the Point count to 6 and the
Degree to 5.
Create the 3-D Curves
So far, you have been working with two-dimensional curves. In order to loft the surfaces,
these planar curves will be used to create to three-dimensional curves and the planar curves
can be discarded.
With the 3D Lines layer current, select the profile and plan view representations of each
curve. Use the Crv2View command to create the three-dimensional curve that combines the
x-, y-, and z-coordinates of the two-dimensional curves. The two-dimensional curves must be
planar for this command to work.
Create the three-dimensional curves
1
Set the 3D Lines layer current.
2
Select the plan and profile
representations of the sheer curve.
3
Start the Crv2View command.
The three-dimensional representation of
that curve will be created.
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When you are satisfied that the proper
curve was created, delete or Hide the
two-dimensional representations.
5
Repeat the Crv2View command for the
chine curve.
L O F T
A
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H U L L
About the Curves
For the loft process to work on the bottom panel, it cannot come to a point. The lofted shape
must be rectangular. This is why the curves are extended beyond the centerline. The curves
can be lofted into a rectangular surface that can then be trimmed back. The curves in the
Victory model are already extended for you except for the bottom centerline curve.
Create the extended curve
1
Start the Curve command.
2
Use the Near object snap to place the
first three control points along the
centerline.
3
Draw the curve so it aligns nicely with
the chine and sheer curves in the plan
view as illustrated.
4
Split the centerline curve with the curve
extension and Join the curve extension
to the aft part of the split centerline.
This creates a new bottom curve to use
for the surface loft.
Loft the Hull Surfaces
Now that you have created a set of edge curves for the side and bottom, create lofted
surfaces from these curves. Start by lofting the bottom surface. Once you have finished it,
use its upper edge as the curve from which to loft the side panel.
To loft the bottom panel, select the two edges (chine and centerline) and use the Loft
command. In this case, be sure to select the new centerline you created in the previous step.
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Loft the side and bottom and the chine and centerline
1
Select the chine and 2-D centerline.
Start the Loft command.
2
In the Loft Options dialog box, under
Cross-section curve options, select
Rebuild with..., and set the control
point count to 15, click OK.
3
Repeat the Loft for the side panel,
selecting the surface edge and the sheer
curve. Loft with the same settings in the
Loft Options dialog.
Trim the Bow and Bottom
When you have successfully created both the side and bottom surfaces, construct a buttock
one-half inch off the centerline and trim both surfaces to this buttock. To do this, in the Top
viewport, draw a line longer than the hull and one-half inch to the right of centerline.
Draw the trim line
1
In the Top viewport, draw a Line along
the x-axis that is longer than the hull.
2
In the Top viewport, offset the line 1/2”
toward to hull surfaces.
Trim the side and bottom to the trim line
Use the Trim command to trim the side
and bottom as illustrated.
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Build the Transom
Like all surfaces in this tutorial, the transom will be built with a surface larger than the
finished surface and then trimmed to the hull.
To make sure there is enough surface area to trim, Extend the transom centerline by a foot
or two both above the sheer and below the centerline. Trim the hull surfaces with the
transom centerline.
Extend the centerline
1
Start the Extend command.
2
At the Select boundary objects or enter extension length. Press Enter for
dynamic extend prompt, press Enter.
3
Select curve to extend… prompt, in the Front viewport, select near the top of the
transom centerline.
4
At the End of extension prompt, select
a point above the current top of the
transom centerline.
5
At the next Select curve to extend…
prompt, select near the bottom of the
transom centerline.
6
At the End of extension prompt, select
a point below the current bottom of the
transom centerline, press Enter.
Trim the hull surfaces
1
Select the transom centerline.
2
Start the Trim command.
3
In the Front viewport, at the Select
object to trim… prompt, select the hull
side and bottom surfaces aft of the
transom centerline. Set
UseApparentIntersections=Yes.
Mirror the Hull and Create the Keel Surface
In the Right or Top viewport, Mirror the two hull surfaces about the centerline. Use the
EdgeSrf command to create surfaces between the two hull halves.
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Mirror the hull surfaces
1
Select the two hull surfaces.
2
Start the Mirror command.
3
In the Top viewport, at the Start of
mirror plane… prompt, type 0, press
Enter.
4
At the End of mirror plane prompt,
with Ortho on, drag the mirror plane
along the x-axis, and click.
Create the keel surface
1
Start the EdgeSrf command.
2
At the Select 2, 3, or 4 curves prompt,
select the two inner edges of the hull
bottom along the keel.
3
Repeat the EdgeSrf command.
4
At the Select 2, 3, or 4 curves prompt,
select the two inner edges of the hull
sides along the keel.
Extrude the Transom Surface
To create the transom surface, Extrude the transom centerline.
Extrude the surface
1
In the Front viewport, select the
extended transom centerline.
2
Start the ExtrudeCrv command.
3
At the Extrusion distance prompt, set
BothSides=Yes and Mode=Straight.
In the Perspective viewport, drag the
extension beyond the hull surface.
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Trim the Transom
Trim the transom surface with the hull and a line from the hull edges.
Trim the transom
1
Draw a line between the two hull edges.
2
Start the Trim command.
3
At the Select cutting objects prompt,
select all of the hull surfaces, including
the keel surface and the line at the top of
the hull, press Enter.
4
At the Select object to trim… prompt,
select the transom surface outside of the
hull lines, press Enter.
Complete the Transom
The transom is now complete. Join the all
surfaces. Use the ShowEdges command to
check that the join was successful. Display the
naked edges. Naked edges are surface edges
that are not joined to other surfaces. In this
case, the only naked edges should be the ones
you expect around the outside of the hull
surfaces – not those between the surfaces.
When you have your surfaces built and joined,
and have no unjoined edges, look at the
surface with the curvature analysis tools.
Add the Deck
The last step is to create the deck surface. In the
profile lines, two curves describe the silhouette
of the deck curve. You will use this curve to
create the deck.
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Draw the Cross-section Curve for the Deck Surface
Use the Project command to project the vertical line to the side of the hull. This line will act
as a marker for the end of the curve. In the Front viewport, draw a curve from the end of
the deck centerline curve to the end of the projected curve on one side of the hull. Use
Planar mode to keep the curve planar. Place the first three control points using Ortho to
keep them lined up at the center.
Project the vertical deck edge to the hull
1
Select the hull and the vertical line.
2
In the Front viewport, use the Project
command to project the curve to the
hull.
The curve will project to both sides of
the hull, so you can draw your crosssection curve on either side.
Draw the cross-section curve
1
Click the Planar pane in the status bar
to turn on Planar mode.
2
In the Front viewport, use the Curve
command to draw a control point curve
from the top end of the deck centerline
curve to the top of the curve projected to
the hull.
Use Ortho to place the first three control
points in a straight line.
Use the End object snap to place the last
point at the top of the projected curve on
the hull.
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Create the deck surface
1
Use the Sweep2 command to create the
deck surface.
2
At the Select rail curves prompts,
select the centerline curve and the hull
edge.
3
At the Select cross section curves…
prompt, select the cross-section curve
you created from the deck centerline
curve to the projected curve on the hull,
press Enter
4
Use the Mirror command to copy the
deck surface to the other side.
At the Start of mirror plane… prompt,
in the Top viewport, type 0, press
Enter.
5
At the End of mirror plane… prompt,
in the Top viewport, drag the mirror
plane with Ortho on.
6
Use the EdgeSrf command to create the
small triangular surface at the tip of the
bow.
7
Join all the surfaces.
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Tutorial: Trace Images
This tutorial demonstrates how to get started
modeling an object using photographs as
reference material.
You will learn how to:
x
x
x
Note
Trace an image to create profile curves.
Create cross-section curves for lofting the
profiles.
Edit control points to change a surface
shape.
The top and side views are actually of different specimens of this dragonfly. In the
side view, the wings are folded up. We will be using the side view image only to draw
the side view curves of the body.
Draw the Body
Since the dragonfly is symmetrical in the top view, and the model is not going to be a
scientific reproduction, trace one side of the dragonfly and mirror the curve to the other side.
For the side view, draw two curves since the profile is not symmetrical. Then we will loft cross
section curves to make the body. The head will be made separately.
The tail and body will all be made in one piece. The tail is actually several segments that flex.
If you were making an animation or a scientific model, you probably would want to divide the
dragonfly into smaller surfaces.
The background bitmap images can be displayed in either color or grayscale.
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Set up the images
1
Use the Line command to draw a reference line the length you want the dragonfly to
be.
Use grid snap or enter a distance to control the length of the line.
2
In Windows Explorer, navigate to
the folder where the tutorial models
are stored.
To find this folder, on the Rhino Help
menu, click Learn Rhino, and then
click Open Tutorial Models.
In the tutorial folder, you will find the
two images you need for this exercise.
Copy these images to convenient folder.
3
Start the BackgroundBitmap
command with the Place option.
4
Open the image file DragonFly
Top.jpg.
Place the image in the Top viewport.
5
Repeat the BackgroundBitmap
command for the side-view.
Place the side-view image in the Front
viewport.
6
With the BackgroundBitmap
command Align option, place the
images so the reference line runs
through the center of the image in both
views.
Draw the outline curve
1
Use the Curve command to draw a plan
view outline of the dragonfly.
Draw only up to the neck. You will be
creating the head another way.
In the Top viewport, you can trace one
side and then use the Mirror command
to copy the curve around the reference
line.
The photograph shows that the dragonfly
is not symmetrical about its centerline.
However, your dragonfly will be
somewhat stylized to make drawing it
easier.
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2
In the Front viewport, use the Bend
command to bend the curves down at
the tail to match the bend in the body
curve in that view.
3
In the Front viewport, trace the body
outline using two curves, one above the
reference line and one below the
reference line.
T R A C E
I M A G E S
Maximize the viewport and zoom in. Pick
only as many points as you need to
create the curves. Use more points when
rounding a corner and fewer points for a
straight section.
Create the body surface
1
Use the CSec command to create crosssection profile curves through the top,
bottom, and side curves.
Draw only as many cross-section curves
as you need to maintain the detail. You
will be able to see whether you have
enough curves when you loft the surface
in the next step. If you do not have
enough curves to maintain the shape in
an area, you can add more and retry the
surface loft.
2
Select all the cross-section curves you
just created.
3
Use the Loft command to create a
surface through the cross-section
profiles.
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Draw the Head
Draw the head with an ellipsoid and move the control points around to deform the head. The
eyes are also ellipsoids. The neck is a surface blend.
Draw the head
1
Use the Ellipsoid command to draw the
head shape.
Use the Diameter option and start the
ellipsoid in the Front viewport to
approximate the head shape.
In the Top viewport, approximate the
head size from side to side.
2
Use the Rebuild command to add more
control points to the ellipsoid.
Set the point count to 16 in the udirection and 10 in the v-direction.
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3
Use the PointsOn command to turn on
control points for the ellipsoid.
4
In the Top viewport, select and drag points on both sides of the ellipsoid toward the
back to deform the head.
5
In the Right viewport, drag the middle two rows of points down.
Blend the Head and Body
The neck is a blend surface between the head shape and the body. First, you are going to
trim the head shape to make an opening.
Draw the neck
1
In the Front viewport, draw a line as
illustrated and use the Trim the head
shape with the line.
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T R A C E
I M A G E S
Use the BlendSrf command to make a
blend surface between the head and
body.
Be sure the seams are aligned and the
direction arrows point the same way.
Draw the Eyes
The eyes are simple ellipsoids.
Draw the eyes
1
Use the Ellipsoid command to draw the
eye.
Base the size and position on the bitmap
background.
2
Use the Move and Rotate commands to
adjust the position of the eye.
3
Use the Mirror command to copy the
eye to the other side.
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I M A G E S
Shape the Tail
The end of the tail has a rounded shape cut out of it. Use a Boolean to make this shape.
Cut the tail
1
If necessary, extend the tail section by
turning on the control points and
dragging them to match the bitmap.
2
Use the Cap command to make the body
into a solid.
3
Use the Cylinder command to draw a
solid cylinder so it cuts through the tail
as illustrated.
4
Use the BooleanDifference command
to cut the end out of the tail.
Trace the Wings and Legs
The wings are solids created from closed curves. The legs are created by tracing a polyline
down the center of a leg and using a pipe surface to make a series of tubes around the
polyline.
Draw the wings
1
In the Top viewport, use the Curve command to trace the wings on one side of the
dragonfly.
2
Make the curves into thin solids with the ExtrudeCrv command.
Use the Cap=Yes and BothSides=Yes options.
3
Position the wings on the back with the
Move command.
Consult the side view image of the
dragonfly. The front wing is slightly
higher than the back wing.
4
Use the Mirror command to copy the
wings to the other side.
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T R A C E
I M A G E S
Draw the legs
1
In the Top viewport, use the Polyline
command to trace down the center of
the legs.
2
Edit the control points to position the
legs in the Top and Front viewports.
You will have to use your imagination a
little for this since the two pictures do
not show the legs of the same insect.
3
Use the Pipe command to draw the legs
around the polylines.
Refer to the background picture to
determine the starting and ending
diameter of the pipe.
4
Use the Mirror command to copy the
legs to the other side, or draw different
legs for the other side.
Finish the Model
Add colors and textures and render.
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T U T O R I A L :
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C U R V E S
O N
A
S U R F A C E
Tutorial: Wrap Curves on a Surface
This tutorial demonstrates wrapping text solids
and other objects on a cylinder. These objects
could be used to trim holes in the cylinder.
You will learn how to:
x
x
Create text as solid objects.
Wrap the objects to a surface.
Make a Surface
For this example, create a simple cylinder. Once you have learned the basic technique, you
will be able to use other types of surfaces. Remember that trimmed surfaces maintain their
basic rectangular shape. This underlying shape will affect the placement of the text.
Create a cylinder
1
In the Top viewport, use the Cylinder
command with the Vertical option to
create a solid cylinder.
2
(Optional) Use the Explode command to
separate the cylinder into three surfaces
and Delete the top and bottom of the
cylinder.
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C U R V E S
O N
A
S U R F A C E
Create the Objects to Wrap
These solid objects will be wrapped on the cylinder surface.
Create the text
1
Use the TextObject command to create
your text using Solids.
Choose a font that is fairly large and
blocky rather than one with many
details.
Set the Height at about 1.5 units.
Set the Solid thickness to .1 units.
2
Place the text on the construction plane
near the cylinder. The location is not
important.
Control the Placement of the Objects
The CreateUVCrv command generates the planar border curves of a surface that can be
used as a guide to orient your text. Use the border rectangle to lay your text out before reapplying it to the cylinder. The rectangle then is used as a reference to guide the placement
of the other objects.
Fine-tune the size and placement
1
Select the cylinder and use the
CreateUVCrv command to create curves
that represent the border of the
untrimmed surface on the construction
plane. In this case a rectangle is created
starting at 0,0 on the Top construction
plane.
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T U T O R I A L :
2
W R A P
C U R V E S
O N
A
S U R F A C E
Select the cylinder and use the
Properties command to turn off the
isocurve display on the cylinder.
This will show you where the seam of the
surface is located. The seam location is
important because the rectangle edges
match the top and bottom of the cylinder
and the seam. Knowing where the seam
is will help you visualize how the text will
be laid out on the cylinder.
In our example the cylinder is rotated so
the seam is toward the back in the view.
3
Move, Rotate, and Scale the text to
arrange it inside the rectangle.
Add any other decoration curves you
want to use.
4
Use the PlanarSrf command to make the rectangle into a surface.
You will use this surface later as a reference object.
Extrude the decoration curves
1
If you have created other curves, select
these.
2
Use the ExtrudeCrv command to
thicken the decorations to match the
letters.
3
At the Extrusion Distance… prompt,
set Cap=Yes.
4
At the Extrusion distance… prompt,
type .1.
Wrap the lettering on the cylinder
1
Select the lettering and the decoration.
2
Start the FlowAlongSrf command.
3
At the Base surface… prompt, set
Rigid=No.
4
Click the rectangular plane near the
“lower-left” corner as illustrated.
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T U T O R I A L :
5
W R A P
C U R V E S
O N
A
S U R F A C E
At the Target surface… prompt, click
the cylinder near the lower edge of the
seam as illustrated.
The text solids wrap around the cylinder.
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T R I M S
Tutorial: Blends and Trims
At first glance, this camera model looks
complex. But after a little analysis, you’ll see
that it’s made of a three basic blocks, glued
together liberally with blends. The three basic
blocks are the body, the viewfinder, and the
lens housing.
The primary tool used to make this model is
the BlendSrf command. It creates smooth,
curvature-continuous blends between two or
more surfaces. This demonstration shows
several ways of creating surfaces (and more
importantly the gaps between surfaces) that
are amenable to blending.
The creation of the model can be broken into seven steps:
1
Create basic body shape.
2
Blend the front and back edges.
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T U T O R I A L :
3
Trim a hole in the body for the
viewfinder.
4
Create the viewfinder surface.
5
Blend between the body and the
viewfinder.
6
Boolean bottom surface and blend
bottom edge.
7
Create lens and blend to body.
B L E N D S
A N D
T R I M S
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T R I M S
Start the Model
1
On the Rhino Help menu, click Learn Rhino, and then click Open Tutorial Models.
2
Open the model file Camera.3dm.
The model is organized into layers that follow the steps. You can open this model and
follow along with the instructions by turning the layers on and off.
Almost every stage involves the creation of a surface that will later be blended to
create the smooth, organic model shown above.
Create Basic Body Shape
The basic body shape is made of three trimmed surfaces. All three are made with extrude
commands. The first step in creating these surfaces is to create the curves that define them.
Create profile curves for front and back surfaces
Both the front and back surfaces have a slight curve. The back surface curves in one
direction, and is most easily made using the ExtrudeCrv command to extrude a
curve. The front surface is curved in two directions, so it is made by extruding one
curve along another.
1
In the Top viewport, use the Curve
command to draw curves 1 and 2.
Use the minimum number of control
points necessary to create the shape.
Keeping control points to a minimum
keeps file sizes smaller, makes surfaces
smoother, and makes future modeling
tasks faster and easier. Notice that the
control points are symmetrical. This
ensures that the curve is symmetrical. In
addition, the middle three control points
are lined up parallel to the x-axis. This
makes a nice smooth, flat curve that is
exactly tangent to the x-axis.
2
Draw curve 3 in the Right viewport.
Start it at the endpoint of curve 2 and
use Planar mode to keep the curve lined
up.
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T R I M S
Extrude the front and back surfaces
1
To create the back surface, use the
ExtrudeCrv command to extrude curve
1 in the z-direction.
Estimate the height. Make sure it is taller
than curve 3. The height is not
important, since the top will be trimmed
off with the side surface.
2
To make the front surface, use the
ExtrudeCrv command to extrude curve
2 along curve 3.
Create profile curve for side surface
`
With the Curve command, create a
profile curve for the side surface.
Create this curve in the Front viewport.
Be careful to make the curve start and
end exactly at the edge of the surface. If
the curve stops short, or extends beyond
the bottom of the existing surfaces, the
trim used in the next step will fail.
Extrude the side surface
`
With the ExtrudeCrv command, extrude
the profile curve toward the back.
Make sure it fully intersects both the
front and back surfaces. An incomplete
intersection will make the trims in the
next step fail.
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T R I M S
Trim and join the surfaces
Trim the three surfaces.
1
Use the Trim command to trim the front
and back surfaces with the extruded side
surface.
2
Use the Trim command to trim the side
surface with the front and back surfaces.
Blend the Front and Back Edges
A blend surface matches smoothly (the blend surface has curvature continuity along the
edges shared with the other surfaces) between two or more surface edges. Blend surfaces
were used for both the front and back edges of the camera body. Two techniques for
trimming the surfaces to open up a gap for blending are shown in this step.
Trim the front surface
The most straightforward and flexible method to create a gap for the first blend is to
trim each surface with curves. This method allows the blend surface to vary in width
at different points along the blend.
1
Hide the back and side surfaces.
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T U T O R I A L :
2
In the Front viewport, use the Curve
command to draw a profile curve.
3
Use the Trim command to trim the
surface with the profile curve.
B L E N D S
A N D
T R I M S
Trim the side surface
1
Use ShowSelected command to unhide
the side surface.
2
In the Right viewport, use the Curve
command to draw a profile curve.
This curve is planar and lies on the
construction plane in the Right viewport.
3
With the Trim command, trim the side
surface with the profile curve.
Blend between front and side surfaces
There are several options for creating blend surfaces. It is easiest to start with the
defaults and see if the result is to your liking. The following illustrations show the
results of using the default option.
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T U T O R I A L :
1
B L E N D S
A N D
T R I M S
Use the BlendSrf command to create a
surface between the front and side
surfaces.
If you simply allow the surface to be
created from the defaults, the corners
will be rather square and the way the
surface travels around the bends is not
very smooth.
2
To improve this, delete the original blend
and make a new blend.
The BlendSrf command lets you control
the cross-sections of the blend. In this
case set the bulge height to around .7
and then place cross section curves
along the opening to control how the
surface will move around the curves.
When Rhino creates a blend, it creates a
series of sections between the two
surfaces to blend. These sections flow
smoothly from one surface to the other.
The number of sections you need
depends on the complexity of the
blend—use more cross-sections for more
complex blends.
Blending the back edge
Another approach for creating a gap to blend is to create a fillet surface. A fillet
surface has a constant radius. In the process of creating the fillet surface, both
surfaces that are being filleted are trimmed with the new surface. You can then delete
the fillet and replace it with a blend. You can also create a variable width blend
surface with this method, but it is not as flexible as the previous technique.
1
Use the FilletSrf command to create a
rolling ball fillet surface between the
back surface and the side surface. Use
the Trim=Yes option and a radius of
0.7.
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T U T O R I A L :
2
Delete the fillet surface.
3
Use the BlendSrf command to create a
blend surface in place of the fillet
surface.
B L E N D S
A N D
T R I M S
Place extra cross-sections around the
corners.
The results may look almost identical in these pictures – and they are, almost – but
when the model is shaded and rotated, the blend surface matches the back and side
surfaces more smoothly because of the curvature continuity of the blend. Fillets are
only tangent to the surfaces, blends are curvature continuous. Try it yourself to see
the difference.
4
Use the Join command to join all the
surfaces together into a polysurface.
Trim the Body for the Viewfinder
The viewfinder bulges out of the body. This bulge houses the viewfinder window and the
necessary optical components that let you look through the camera. As with the rest of the
camera, the viewfinder should blend in smoothly with the rest of the body.
The blend is made with the same approach used to create the front surface blend: trim both
parts and create a blend surface between them. Since the camera body is actually a
polysurface, and the blend fills a more complex hole, more steps are required to create the
blend.
Create body trimming profile curve
The viewfinder will wrap around the top of the body. This means that the hole in the
body needs to wrap around the top, too.
1
With the Curve command, draw a rough
approximation of the hole the Front
viewport. Draw the curve symmetrical
about the y-axis.
Ensure the symmetry by drawing half the
curve, mirroring it about the y-axis, and
joining the two sides. The last two
control points (the ones at the end where
the two halves meet) are lined up
horizontally to ensure the curve doesn’t
have a kink when mirrored.
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T U T O R I A L :
2
B L E N D S
A N D
T R I M S
Press F10 to turn on control points and
move them to get the curve to wrap
around the surface.
Drag the control points in the Right
viewport. Turn on Ortho so that the
control points only drag parallel to the
world y-axis.
Pull the trimming profile curve onto the body surfaces
Now that the curve wraps around the body polysurface, you will pull the curve back
to the surfaces.
You need to pull the curve to each surface separately, resulting in a series of curves.
1
Use the Pull command to pull the curve
to each surface separately, resulting in a
series of curves.
2
Delete extra curves until you have a
series of curves around the surfaces that
match the original curve as illustrated.
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T R I M S
Split the body parts with the curve
1
Use the Split command to split each
surface with the pullback curves.
2
Delete the unnecessary geometry as
illustrated.
Create the Viewfinder
The next step in creating the viewfinder is to create the main shape of the viewfinder surface.
It is a simple extruded surface trimmed to complement the hole in the body.
Create the viewfinder surface
1
In the Right viewport, use the Curve
command to draw a profile curve for the
viewfinder surface.
2
Use the ExtrudeCrv command to
extrude the curve in both directions from
the center profile.
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T R I M S
Create viewfinder trimming curve
To create the viewfinder trimming curve, start with the curve that was pulled back to
the camera body.
1
Use the Scale1D command to scale the
curve several times to get the curve
roughly the right shape.
Scale the pullback curve vertically in the
Right viewport.
Scale the pullback curve horizontally in
the Front viewport.
2
The final shape is achieved with control
point editing.
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T U T O R I A L :
3
With the Pull command, pull the
resulting curve back to the surface.
4
Use the Trim command to trim the
surface with the curve.
B L E N D S
A N D
T R I M S
Blend between the Body and the Viewfinder
Blending between the body and the viewfinder surface is more difficult than the blends
between the front, back and sides because it follows such a complex path.
To create the blend between the body and viewfinder
1
Start the BlendSrf command.
2
Select all the edges on the body surface
(in order), then select all the edges for
the viewfinder.
3
Add enough cross sections so that the
transitions around the tight turns at the
back are smooth.
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T R I M S
Create Bottom of Camera
At this point, the bottom of the camera is open. To close it, draw a curve that represents the
bottom, extrude it, and use Boolean intersection to trim and join the surfaces.
Create the bottom surface
1
In the Front viewport, draw a profile
curve with the Curve command.
2
With the ExtrudeCrv command, extrude
this profile curve beyond the front and
back of the camera.
3
With the Dir command, check the
direction of the surfaces to ensure the
body points out, and the bottom points
down.
Use the Flip option to correct the
direction if necessary.
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T U T O R I A L :
4
B L E N D S
A N D
T R I M S
Use the BooleanIntersection command
to trim and join the two surfaces in one
step.
Create bottom edge blend
We have used trimming and filleting to create a gap between surfaces for blending. A
third technique for creating a gap for a blend is to create a pipe around the edge,
split the surfaces with the pipe, and blend between them. This usually gives a slightly
different result than the fillet technique.
1
To create the pipe, with the ExtractSrf
command, extract the bottom surface
from the polysurface.
2
Use the DupBorder command to create
a single closed border curve.
This creates a curve that can be used to
create the pipe.
3
With the Pipe command, create a pipe
surface around the duplicated border.
Use a radius of 0.5.
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T U T O R I A L :
4
With the Split command, trim the body
and the bottom with the pipe.
5
Delete the unnecessary pieces, including
the pipe.
B L E N D S
A N D
T R I M S
Blend surface on bottom surface
1
With the BlendSrf command, create a
blend to fill the gap.
2
With the Join command, join the parts
together.
Create the Lens and Blend between the Body and the Lens
The last step is to create the lens and to blend the surface between them.
Create the lens profile curve
1
With the Polyline command, draw the
upper half of lens profile curve.
2
With the Fillet command, fillet the
polycurve in a few places to round of
some of the sharp corners.
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T U T O R I A L :
3
B L E N D S
A N D
T R I M S
Use the Revolve command to create a
revolved surface from the profile curves.
Snap to end 1 as illustrated for the
beginning of the revolve axis. Use Ortho
to make the revolve axis parallel to the
world y-axis.
Split body and lens with pipe
Blend between the body and the lens the same way the bottom edge was blended.
1
With the Intersect command, create the
intersection curve between the body and
the lens surface.
2
With the Pipe command, create a pipe
surface around the intersection curve
with a radius of 0.15.
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T U T O R I A L :
3
Split the lens and body with the pipe.
4
Delete the pipe and the extra surfaces.
5
With the BlendSrf command, fill the gap
with a blend surface between body and
lens.
6
Set material properties and render.
B L E N D S
A N D
T R I M S
112
M O R E
H E L P
More Help
The Rhino Help file is the major resource for detailed information on specific commands.
To get help on a specific command
To get Help for a command, press F1 while the command is running.
On the Rhino Help menu, click Command Help.
The Rhino Help will display in a dockable window.
Click Auto-Update to display the Help topic for the current command.
The Help window appears with the specific command topic visible.
Help on the Internet
Find the answers to frequently asked questions at:
http://www.rhino3d.com/support.htm.
For technical support, send email to: [email protected]
Chat with other Rhino users on the Rhino newsgroup at:
news://news.rhino3d.com/rhino.
Participate in the Rhino Wiki at: http://www.rhino3d.com/wiki.htm.
Find tutorials, examples, books, and links about Rhino at: www.rhino3d.com/resources.
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