2009

Table Of Contents
and once with software rendering. In such cases, youll need to composite
the two sets of rendered images using a compositing software package.
Lesson 2: Rigid bodies and constraints
Introduction
In Maya, a rigid body is a surface which has the attributes of an unyielding
shape. Unlike conventional computer surfaces, rigid bodies collide rather than
pass through each other during animation and are used for creating dynamic
simulations. As well, rigid surfaces do not deform when they collide with
other objects in Maya.
Rigid bodies can be created from polygonal or NURBS surfaces. Rigid body
attributes can be assigned to the surfaces so they act and react in a simulation
in specific ways. Examples of rigid body attributes are velocity, mass, and
bounce.
To animate rigid body motion, you can use fields, keyframes, expressions,
rigid body constraints, or collisions with particles or other rigid bodies.
Rigid body constraints restrict the motion of rigid bodies. The constraints
simulate the behavior of real-world items youre familiar with, such as pins,
nails, barriers, hinges, and springs.
In this lesson, you create a rigid body dynamic simulation in which you drop
a ball on some planks and watch the simulation in action. In this lesson you
learn how to:
Create objects with physical properties.
Apply hinge constraints to objects so they react in specific ways.
Set attributes for the rigid bodies to be either active or passive for the
simulation.
Play back a rigid body dynamic simulation.
494 | Chapter 10 Dynamics