ContactFilter

Description

A contact filter is used to control what contacts are created when intersecting other shapes. A contact filter contains a filter with the addition of a group index allowing overrides to the filter.

See ContactFilterMode.

Build a PhysicsMask for the layer the object is on and another PhysicsMask for the layers it collides with. Pass both into a ContactFilter and assign it to PhysicsShapeDefinition.contactFilter before you create the shape. PhysicsLayers.GetLayerMask gets the layer mask whether the project uses GameObject layers or the Physics Core 2D API layers. Use PhysicsMask.All to represent all layers, or PhysicsMask.None to represent no layers.

Additional resources: PhysicsMask, PhysicsLayers.GetLayerMask, PhysicsShapeDefinition.contactFilter

 // The following example sets a falling circle to be on the MyNewLayer layer
 // and collide only with other MyNewLayer layer objects. Create a Physics Core
 // Settings 2D asset, enable Use Physics Layers, and add a layer called MyNewLayer
 // before you enter Play mode.
 using UnityEngine;
 using Unity.U2D.Physics;

 public class ContactFilters : MonoBehaviour
 {
     void Start()
     {
         CircleGeometry smallCircleShape = new CircleGeometry { radius = 0.5f };
         CircleGeometry largeCircleShape = new CircleGeometry { radius = 3f };

         PhysicsWorld world = PhysicsWorld.defaultWorld;

         // Create a small falling circle.
         PhysicsBody object1 = world.CreateBody(new PhysicsBodyDefinition
         {
             position = new Vector2(0.5f, 8f),
             type = PhysicsBody.BodyType.Dynamic
         });

         // Create a shape on the MyNewLayer layer, which only collides with the MyNewLayer layer.
         PhysicsMask objectLayer = PhysicsLayers.GetLayerMask("MyNewLayer");
         PhysicsMask collisionLayer = PhysicsLayers.GetLayerMask("MyNewLayer");
         PhysicsShape.ContactFilter contactFilter = new PhysicsShape.ContactFilter
         {
             categories = objectLayer,
             contacts = collisionLayer
         };
         PhysicsShapeDefinition smallCircleDefinition = new PhysicsShapeDefinition
         {
             contactFilter = contactFilter
         };
         object1.CreateShape(smallCircleShape, smallCircleDefinition);

         // Create a larger static circle below, on the default layer.
         PhysicsBody object2 = world.CreateBody(new PhysicsBodyDefinition
         {
             position = new Vector2(0f, 0f),
             type = PhysicsBody.BodyType.Static
         });
         object2.CreateShape(largeCircleShape);
     }
 }

Static Properties

Properties

Constructors

Public Methods