Abstract: Internet-based navigating of large-cale terrain environments is an important aspect of distribute virtual reality applications such as flight simulations and military maneuver, but currently is restricted by the limited network bandwidth. The authors exploit the potential of terrain as stream media and propose a new data lay-out that facilitates network transmission. By taking advantage of the regularity of DEM, terrain data are organized into multiple progressive compressed streams. Runtime network throughput is effectively reduced by intra- and inter-frame coherence. Coupled with carefully designed transmission scheme, the algorithm is decreased and can accommodate to dynamically changed network bandwidth.

Key words: terrain navigation, streaming, progressive compression

摘要： 基于网络的三维地形场景漫游在军事、教育、娱乐等领域有广泛的应用，但目前受限于有限的网络带宽而无法满足用户实时的需求。综合考虑了地形场景漫游过程与视频播放之间的相似性，从流式传输的观点出发，利用地形数据规则采样的特点，设计了全新的地形数据组织方式，将地形数据表示为多条渐进压缩码流。运行时刻则充分利用了漫游过程的帧内及帧间相关性，并与传输策略相结合，有效降低了远程地形场景漫游过程中的数据吞吐量，并且能够自适应网络带宽的动态变化。

关键词: 地形场景漫游, 流式传输, 渐进压缩