Maya has two kinds of rigid bodies—active and passive. An active rigid body is animated by dynamics—fields, collisions, and springs—not 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, you’ll change the bottom plank to be a passive rigid body so the ball bounces off the plank but the plank doesn’t react to the collision.

To change an active rigid body to a passive rigid body

1. Select pCube1 and display the Attribute Editor.
2. Click the rigidBody1 tab to display the rigid body attributes.
3. In the Rigid Body Attributes section, turn off Active to make pCube1 a passive rigid body. Hide the Attribute Editor.

   

4. Go to the start of the playback range and play the animation.

   Observe how pCube1 no longer reacts to the impact of the ball, but the ball continues to bounce off it.

   planksPassive.mov