public override void CreateEngineInstance(bool bCreateChildren) { base.CreateEngineInstance(bCreateChildren); _lastParent = (CustomVolumeShape)Parent; if (_engineInstance == null) { Debug.Assert(Parent != null, "Need a parent to create the engine instance"); _engineInstance = new EngineInstanceCustomVolumeVertex((Shape3D)Parent); _engineInstance.SetPosition(Position.X, Position.Y, Position.Z); } }