The collisionA collision occurs when the physics engine detects that the colliders of two GameObjects make contact or overlap, when at least one has a Rigidbody component and is in motion. More info
See in Glossary matrix tables on this page describe which event messages Unity generates based on the configuration of each colliderAn invisible shape that is used to handle physical collisions for an object. A collider doesn’t need to be exactly the same shape as the object’s mesh - a rough approximation is often more efficient and indistinguishable in gameplay. More info
See in Glossary in a collision pair.
When a pair of colliders make contact, they generate collision detectionAn automatic process performed by Unity which determines whether a moving GameObject with a Rigidbody and collider component has come into contact with any other colliders. More info
See in Glossary messages if the following are both true:
The following table describes each combination of collider types. A “Y” indicates a combination that can generate collision detection and collision messages.
| Collision detection occurs and messages are sent upon collision | ||||||
|---|---|---|---|---|---|---|
| Static collider | Dynamic collider | Kinematic collider | Static trigger collider | Dynamic trigger collider | Kinematic trigger collider | |
| Static collider | Y | |||||
| Dynamic collider | Y | Y | Y | |||
| Kinematic collider | Y | |||||
| Static trigger collider | ||||||
| Dynamic trigger collider | ||||||
| Kinematic trigger collider | ||||||
Remember that Unity only applies physics forces to collider GameObjectsThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info
See in Glossary 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:
The following table describes each combination of collider types. A “Y” indicates a combination that can generate trigger messages from any trigger collider in the pair.
| Trigger messages are sent upon collision | ||||||
|---|---|---|---|---|---|---|
| Static collider | Dynamic collider | Kinematic collider | Static trigger collider | Dynamic trigger collider | Kinematic trigger collider | |
| Static collider | Y | Y | ||||
| Dynamic collider | Y | Y | Y | |||
| Kinematic collider | Y | Y | Y | |||
| Static trigger collider | Y | Y | Y | Y | ||
| Dynamic trigger collider | Y | Y | Y | Y | Y | Y |
| Kinematic trigger collider | Y | Y | Y | Y | Y | Y |
Unity collision matrix Unity collision interaction