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
This discrepancy means the Ball scaleY is larger than its scaleX and scaleZ
attributes in the first frame of the animation. Although the difference is minor
in this example, other cases might be more significant.
To start your animation at frame 1 and get the same result as the example,
you can subtract 0.0417 from the attribute:
Ball.scaleY = (time - 0.0417) + 1;
When you go to the start time, the expression sets Ball’s scaleY value to (0.0417
- 0.0417) + 1. This equals 1, its original scaleY value.
Lesson 2: Conditional expressions
Introduction
Conditional statements set one attribute or variable for an expression based
on the condition of another attribute or variable. This means that when a
particular defined condition exists for one attribute then another attribute is
changed based on how the expression defines it to do so.
In this lesson you learn how to:
■ Use conditional statements to control an expression.
■ Refine the conditional statements using if and else statements.
Creating a conditional expression
In the following steps, you create a default sphere and write an expression to
increase its Scale Y attribute based on the animation playback time. In the
first two seconds of the animation time, Scale Y increases with the value of
the time. At two seconds and thereafter, Scale Y no longer increases.
To create an expression using conditional statements
1 Make sure you’ve done the steps in
Preparing for the lessons on page 566.
2 Create a NURBS or polygonal sphere at the origin with an X scale, Y scale,
and Z scale of 1.
3 Name the sphere Balloon.
574 | Chapter 12 Expressions