2009

Table Of Contents
Running a dynamics simulation
In the next steps, you create a ball and add gravity to make the ball drop and
hit the planks and then playback the simulation.
To create a ball for the simulation
1 Select Create > Polygon Primitives > Sphere > .
2 Set Radius to 0.2 and click Create.
3 In the Channel Box, set the Spheres Translate Y value to 18.
To add gravity attributes to the ball
1 With the sphere still selected, select Fields > Gravity.
When you connect Gravity to the sphere, it automatically makes the
sphere an active rigid body. Gravity affects only the object that was
selected when you add the Gravity field.
To run the dynamics simulation
1 In the Time and Range slider, play the animation.
The ball falls and collides with the planks, which rotate about the hinge
constraint.
Changing an active rigid body to passive
Maya has two kinds of rigid bodiesactive and passive. An active rigid body
is animated by dynamicsfields, collisions, and springsnot by keys.
Because the ball and planks are all active rigid bodies, gravity pushes it down
and it rebounds after colliding with the planks.
A passive rigid body can have active rigid bodies collide with it. You can key
its Translate and Rotate attributes, but dynamics have no effect on it.
In the previous steps, all the planks were active rigid bodies and reacted to
the collision of the ball. In the following steps, youll change the bottom plank
to be a passive rigid body so the ball bounces off the plank but the plank
doesnt react to the collision.
498 | Chapter 10 Dynamics