# CollisionEvents.Updated An event raised on every frame when two objects are in contact. ``` struct Updated ``` ## Topics ### Getting the involved entities [`let entityA: Entity`](/documentation/RealityKit/CollisionEvents/Updated/entityA) The first entity involved in the collision. [`let entityB: Entity`](/documentation/RealityKit/CollisionEvents/Updated/entityB) The second entity involved in the collision. ### Characterizing the collision [`let impulse: Float`](/documentation/RealityKit/CollisionEvents/Updated/impulse) The total impulse in this collision pair obtained by adding up all the individual impulses applied at each contact point [`let position: SIMD3`](/documentation/RealityKit/CollisionEvents/Updated/position) A position representing the estimated point of contact. ### Instance Properties [`var contacts: [Contact]`](/documentation/RealityKit/CollisionEvents/Updated/contacts) All contacts between the collision pair. Empty if all contact information is not requested. [`var impulseDirection: SIMD3`](/documentation/RealityKit/CollisionEvents/Updated/impulseDirection) The direction of the total impulse in scene coordinate space. [`var penetrationDistance: Float`](/documentation/RealityKit/CollisionEvents/Updated/penetrationDistance) The estimated distance of overlap between the two colliding entities in scene coordinate space. ## Relationships ### Conforms To [`Sendable`](/documentation/Swift/Sendable) [`Event`](/documentation/RealityKit/Event) [`SendableMetatype`](/documentation/Swift/SendableMetatype) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)