Compound Colliders

Compound collider shapes allow you to place multiple collider shapes on one physics body. You can arrange the shapes into a hierarchy, and adjust the transform of each shape.

A single GameObject with a built-in Rigidbody or a custom Physics Body authoring component can contain multiple child GameObjects that have built-in Collider or custom Physics Shape authoring components. Unity Physics merges these into one compound PhysicsCollider for the physics body, containing a CompoundCollider blob asset whose children have the collider types you specified in the Editor.

This allows you to make complex rigid bodies made of multiple simpler representations, so that the collision detection remains fast yet detailed, and you don't have to settle for a coarse convex hull around the whole object.

In the following example, Body contains a single Rigidbody authoring component that represents a humanoid torso. The child GameObjects contain one Collider authoring component each; four Box colliders to represent limbs and a Sphere collider to represent a head. All child colliders will be regrouped in a CompoundCollider blob asset assigned to the PhysicsCollider component in the rigid body entity that is baked from the Body GameObject.

Compound shape hierarchy

Note

For this example, you must put all GameObjects (Body and its children) in a sub scene so that Unity can perform baking to convert them into entities and components.

The Compound shape in Play mode