If your two colliders don't match in the matrix you will not get trigger messages.
If you're trying to receive events that don't match, consider using a collision event instead, note that they have a different method signature.
| Static | Rigidbody | Kinematic Rigidbody | Static Trigger | Rigidbody Trigger | Kinematic Rigidbody Trigger | |
|---|---|---|---|---|---|---|
| Static | ||||||
| Rigidbody | ||||||
| Kinematic Rigidbody | ||||||
| Static Trigger | ||||||
| Rigidbody Trigger | ||||||
| Kinematic Rigidbody Trigger |
Your two colliders are described by an element in a row and in a column, the intersection of these two shows whether this type of event will be fired.
If the event is not green, consider changing your setup, or switching event type.
A Collider 2D is required on both objects, and at least one object needs a Rigidbody 2D. Their settings are described below:
| Type | Rigidbody | Collider |
|---|---|---|
| Static | None, or Body Type set to Static. |
Is Trigger is off. |
| Rigidbody | Body Type set to Dynamic. | Is Trigger is off. |
| Kinematic Rigidbody | Body Type set to Kinematic. | Is Trigger is off. |
| Static Trigger | None, or Body Type set to Static. |
Is Trigger is on. |
| Rigidbody Trigger | Body Type set to Dynamic. | Is Trigger is on. |
| Kinematic Rigidbody Trigger | Body Type set to Kinematic. | Is Trigger is on. |
Unity, huh, how?