Create Compound Collision Shapes

You can create a single rigid body made of a compound of collision shapes comprised of multiple meshes in the hierarchy. You can also create multiple rigid bodies from selection while skipping objects that already have rigid bodies attached.

Note: For Dynamic and Kinematic bodies, the sub-shapes use the Hull shape type, while static bodies use the Mesh shape type.

To create a rigid body comprised of multiple shapes:

1. Select the object that is made up of multiple objects.
   Tip: You can use the Outliner window (Window > Outliner) to select multiple objects.
2. Select Bullet > Create Active Rigid Body from the Bullet menu. This sets all the selected objects as Active Rigid Bodies.
3. In the Attribute Editor, select BulletRigidBodyShape.
4. Locate Collider Properties and select Compound from the Collider Shape Type menu.
   Note: If you select Collision Shape in the Bullet Solver node, you can see the compound shape outline. A green outline indicates that the compound is set to Initially Sleeping.
When something collides with the compound object, it will react as one piece instead of several.



Examples: A tower made of 1000 bricks in a Rigid Body solve. The first tower is a compound object, while the second has each of its three tiers set as compound objects. The last two images show the individual brick set as Hull and Cube-type objects.