But these new applications confront two major problems . one is the difficulty in the process of modeling and designing of virtual scenes . the other is the restriction posed by transferring the large - scale scenes over the network 然而这些新的应用面临两大瓶颈问题：一是与用户交互的虚拟场景的建模和设计问题，特别是在建筑行业设计中这个问题更为突出；二是大规模虚拟场景的网络传输受目前带宽的限制。
