BoxCollison's OnComponentHit event is not triggered when BoxCollison hits a spawned actor with simulate physics enabled. The event is triggered if the same actor has been placed in the level beforehand. 


Workaround Code in UE5.1

FPhysScene_Chaos::HandleCollisionEvents(const Chaos::FCollisionEventData& Event) 

// Get swapped velocity deltas
const FVector& DeltaVelocity1 = bSwapOrder ? CollisionDataItem.DeltaVelocity2 : CollisionDataItem.DeltaVelocity1;

const FVector& DeltaVelocity2 = bSwapOrder ? CollisionDataItem.DeltaVelocity1 : CollisionDataItem.DeltaVelocity2;

NotifyInfo.Info0.SetFrom(GetBodyInstanceFromProxyAndShape(PhysicsProxy0, bSwapOrder ? CollisionDataItem.ShapeIndex2 : CollisionDataItem.ShapeIndex1), DeltaVelocity1);

NotifyInfo.Info1.SetFrom(GetBodyInstanceFromProxyAndShape(PhysicsProxy1, bSwapOrder ? CollisionDataItem.ShapeIndex1 : CollisionDataItem.ShapeIndex2), DeltaVelocity2);



Steps to Reproduce

1. Open attached project.

2. The vehicle moves forward and collides with a "Spawned" Box.

    Both box and car detected OnComponentHit event and logged.

3. The vehicle moves forward and collides with a "Placed" Box.
    The box detects OnComponentHit event and logs, but the car does not detect the OnComponentHit.


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ComponentUE - Simulation - Physics
Affects Versions5.1
Target Fix5.5
CreatedFeb 20, 2023
UpdatedFeb 27, 2024