/// Set the callback for when an internal tick (simulation substep) happens, optional user info
 public void SetInternalTickCallback(IInternalTickCallback cb, Object worldUserInfo, bool isPreTick)
 {
     if (isPreTick)
     {
         m_internalPreTickCallback = cb;
     }
     else
     {
         m_internalTickCallback = cb;
     }
     m_worldUserInfo = worldUserInfo;
 }
		/// Set the callback for when an internal tick (simulation substep) happens, optional user info
		public void SetInternalTickCallback(IInternalTickCallback cb, Object worldUserInfo,bool isPreTick) 
		{ 
            if (isPreTick)
            {
                m_internalPreTickCallback = cb;
            }
            else
            {
                m_internalTickCallback = cb;
            }
            m_worldUserInfo = worldUserInfo;
        }