The following collision matrix table describe which event messages Unity generates based on the configuration of each collider in a collision pair:
| Collider types | Static collider | Dynamic collider | Kinematic collider | Static trigger collider | Dynamic trigger collider | Kinematic trigger collider |
|---|---|---|---|---|---|---|
| Static collider | No collision event message sent | Collision detection occurs and messages sent on collision | No collision event message sent | No collision event message sent | Trigger messages sent on collision | Trigger messages sent on collision |
| Dynamic collider | Collision detection occurs and messages sent on collision | Collision detection occurs and messages sent on collision | Collision detection occurs and messages sent on collision | Trigger messages sent on collision | Trigger messages sent on collision | Trigger messages sent on collision |
| Kinematic collider | No collision event message sent | Collision detection occurs and messages sent on collision | No collision event message sent | Trigger messages sent on collision | Trigger messages sent on collision | Trigger messages sent on collision |
| Static trigger collider | No collision event message sent | Trigger messages sent on collision | Trigger messages sent on collision | No collision event message sent | Trigger messages sent on collision | Trigger messages sent on collision |
| Dynamic trigger collider | Trigger messages sent on collision | Trigger messages sent on collision | Trigger messages sent on collision | Trigger messages sent on collision | Trigger messages sent on collision | Trigger messages sent on collision |
| Kinematic trigger collider | Trigger messages sent on collision | Trigger messages sent on collision | Trigger messages sent on collision | Trigger messages sent on collision | Trigger messages sent on collision | Trigger messages sent on collision |
When a pair of colliders make contact, they generate collision detection messages if the following are both true:
Trigger colliders don’t generate collision detection messages.
Unity only applies physics forces to collider GameObjects that have a physics body (a Rigidbody or ArticulationBody). When a physics body collider collides with a static collider, only the physics body collider behavior changes as a result of the collision (for example, it might bounce or slow down as a result of the collision).
Trigger messages occur in the following circumstances: