# Collider Collider

The collider component is used to describe the shape of an object in the physical world.

The collider component can be used in conjunction with a rigid body to describe the shape of the rigid body. It can also be used alone. At this time, it is regarded as the collision body attached to a completely stationary rigid body.

# Different collider types

• Basic collision body
  • Cuboid collision body
  • Sphere collision body
  • Capsule collision body-composed of a cylinder plus spheres at both ends
• 3D mesh collision body-3D mesh model can be specified manually

# Important attributes and events

There are two ways to add physical events:

1. (Recommended) Use collider.onCollisionEnter in the script to get the Delegate of the event from the collision body, and then use the following methods to add event callbacks:

   collider.onCollisionEnter.add(collision => {
       // handle collision
   });
   

2. In the user script, directly implement the onCollisionEnter function, and mount the user script on the node where the collision body is located.

   export default class MyScript extends engine.Script {
       public onCollisionEnter(collision: engine.Collision) {
           // handle collision
       }
   }
   

# Trigger

If the isTrigger property is true, the collider will be marked as a Trigger.

The Trigger collision body will not collide with other collision bodies in the physics simulation phase, will not change the motion state of the two due to the collision, and will not generate the onCollisionXX series of events.

In the physics simulation phase, if a Trigger collider and another Triggers intersect, an event of the onTriggerXX series will not be generated.

# Use multiple collision bodies to simulate the shape of objects

Sometimes using a single collider cannot meet the needs, and the three-dimensional mesh collider is too performance-consuming. You can consider creating multiple different colliders on the same object to approximate the shape of the simulation.

# Physical Material

Additional Physical Material*resources can be used to describe the physical properties of the collision body surface.

# ▌Physical material properties

# The relationship between different types of collision bodies

# ▌Which collision bodies can collide

# ▌Which colliders can trigger Trigger events