Inertial Properties Editor

Determine a rigid body's moment of inertia, which is its resistance to angular acceleration. Basically, it specifies how an object spins around its center of mass when dynamics are applied (forces and/or collisions).

To apply: Select an object and choose Create Rigid Body Active or Passive Rigid Body from the Simulate toolbar.

To redisplay: Select the rigid body and choose Modify Rigid Body Edit Rigid Body from the Simulate toolbar. You can also click the rigid body's Inertial Properties icon in the explorer.

For more information, see Setting the Rigid Body's Mass or Density (Inertial Properties) [ Simulation].

Mass

Use Mass	Uses the rigid body's Mass value to determine inertia. If not selected, the Density value is used.
Mass	Mass in kilograms (kg) of the rigid body. The more mass, the more effort it takes to change the object's direction.
Density	The rigid body's mass in relation to its volume. This value is in kilograms per Softimage unit.

Center of Mass

The center of mass is the location at which a rigid body spins around itself when dynamics are applied (forces and/or collisions).

User Center of Mass	Uses the rigid body's center of mass position that you define here in local X, Y, Z coordinates to determine inertia. If you don't select this option, the center of mass is defined at the same location as the object's center (wherever the center is located).
X, Y, Z	The position of the object's center of mass in local space.