The callback will only occur if PhysicsWorld.transformTweenMode is set to PhysicsWorld.TransformTweenMode.Custom and there are transform write tweens available. This will always be called on the main-thread after the simulation has finished. You should avoid write operations on physics objects during this callback. NOTE: When transform tweening, you can calculate PhysicsBody.TransformWriteMode.Interpolate or PhysicsBody.TransformWriteMode.Extrapolate write modes by using PhysicsBody.TransformWriteTween.GetInterpolatedPose and PhysicsBody.TransformWriteTween.GetExtrapolatedPose respectively.

void OnTransformTweenWrite(PhysicsEvents.TransformTweenWriteEvent transformTweenWriteEvent)

TransformTweenWriteEvent