2009
Table Of Contents
- Contents
- Overview
- Maya Basics
- Polygonal Modeling
- Introduction
- Preparing for the lesson
- Lesson 1: Modeling a polygonal mesh
- Introduction
- Setting modeling preferences
- Using 2D reference images
- Creating a polygon primitive
- Modeling in shaded mode
- Model symmetry
- Selecting components by painting
- Selecting edge loops
- Editing components in the orthographic views
- Editing components in the perspective view
- Drawing a polygon
- Extruding polygon components
- Bridging between edges
- Adding polygons to a mesh
- Splitting polygon faces
- Terminating edge loops
- Deleting construction history
- Mirror copying a mesh
- Working with a smoothed mesh
- Creasing and hardening edges on a mesh
- Beyond the lesson
- NURBS Modeling
- Subdivision Surfaces
- Animation
- Introduction
- Preparing for the lessons
- Lesson 1: Keyframes and the Graph Editor
- Lesson 2: Set Driven Key
- Lesson 3: Path animation
- Lesson 4: Nonlinear animation with Trax
- Introduction
- Open the first scene for the lesson
- Creating clips with Trax
- Changing the position of clips with Trax
- Editing the animation of clips
- Reusing clips within Trax
- Soloing and muting tracks
- Scaling clips within Trax
- Open the second scene for the lesson
- Creating clips from motion capture data
- Extending the length of motion capture data
- Redirecting the motion within a clip
- Beyond the lesson
- Lesson 5: Inverse kinematics
- Introduction
- Open the scene for the lesson
- Understanding hierarchies
- Viewing hierarchies using the Hypergraph
- Creating a skeleton hierarchy
- Parenting a model into a skeleton hierarchy
- Applying IK to a skeleton hierarchy
- Creating a control object for an IK system
- Constraining an IK system
- Limiting the range of motion of an IK system
- Simplifying the display of a hierarchy
- Applying parent constraints on an IK system
- Planning an animation for an IK system
- Animating an IK system
- Beyond the lesson
- Character Setup
- Polygon Texturing
- Rendering
- Introduction
- Preparing for the lessons
- Lesson 1: Rendering a scene
- Introduction
- Open the scene for the lesson
- Creating shading materials for objects
- Refining shading materials for objects
- Maya renderers
- Rendering a single frame using IPR
- Rendering using the Maya software renderer
- Batch rendering a sequence of animation frames
- Viewing a sequence of rendered frames
- Beyond the lesson
- Lesson 2: Shading surfaces
- Lesson 3: Lights, shadows, and cameras
- Lesson 4: Global Illumination
- Lesson 5: Caustics
- Dynamics
- Painting
- Introduction
- Preparing for the lessons
- Lesson 1: Painting in 2D using Paint Effects
- Lesson 2: Painting in 3D using Paint Effects
- Introduction
- Preparing for the lessons
- Brushes and strokes
- Rendering Paint Effects strokes
- Paint Effects on 3D objects
- Creating a surface to paint on
- Painting on objects
- Using turbulence with brush stroke tubes
- Using additional preset brushes
- Mesh brushes
- Converting mesh strokes to polygons
- Modifying a converted polygonal mesh
- Beyond the lesson
- Lesson 3: Painting textures on surfaces
- Expressions
- Scripting in Maya
- Index
4 In the Expression Name box, you can optionally enter an expression
name, for instance, ScaleBallHeight.
If you write several expressions in the same scene, giving each a name
might make it easier to find the desired expression if you decide to alter
it later. If you don’t provide a name, the expression receives a default
name, for instance, expression1.
Note that the Attributes list displays Ball’s keyable, unlocked
attributes—the attributes you’ll most likely want to animate with an
expression. Use the scroll bar to see the entire list.
5 Enter this expression in the expression text area:
Type all characters exactly as shown above. Entries are case sensitive. The
semicolon (;) signifies the end of the expression statement. End each
statement in an expression with a semicolon.
An error message appears in the Script Editor and Command Line’s
response area if the expression has incorrect syntax or typing mistakes.
6 Click Create to create the expression.
Creating the expression checks it for syntax errors and converts it to a
form Maya can execute when you return to the start time or play the
animation. Clicking this button also executes the expression for the
current frame.
The expression sets Ball’s scaleY attribute to the value of time + 1.
Ball.scaleY is the full name of the attribute. A period separates the name
of the object and attribute. Note that you must spell the object and
attribute with uppercase and lowercase letters as they appear in the
Expression Editor’s Objects and Attributes lists.
The word time is a commonly used predefined variable that updates as
an animation plays. It contains the elapsed number of seconds from the
first frame to the current frame. The value increases with the increasing
frame number.
568 | Chapter 12 Expressions