计算机科学 ›› 2013, Vol. 40 ›› Issue (Z6): 120-124.

• 数据存储与挖掘 • 上一篇    下一篇

面向大规模地形的瓦片调度与实时绘制算法

刘浩,曹巍,赵文吉,宁方馨,潘李亮   

  1. 首都师范大学资源环境与旅游学院 北京100048;中国科学院地理科学与资源研究所 北京100101;首都师范大学资源环境与旅游学院 北京100048;首都师范大学资源环境与旅游学院 北京100048;北京合歌科技有限公司 北京100085
  • 出版日期:2018-11-16 发布日期:2018-11-16
  • 基金资助:
    本文受国家自然科学基金项目(41001300)资助

Dynamic Scheduling and Real-time Rendering Method for Large-Scale Terrain

LIU Hao,CAO Wei,ZHAO Wen-ji,NING Fang-xin and PAN Li-liang   

  • Online:2018-11-16 Published:2018-11-16

摘要: 随着图形硬件性能的提升,大规模地形绘制的主要瓶颈已从绘制能力不足转变为大数据的传输,针对这一问题提出一种支持大规模地形的瓦片调度与实时绘制算法。将超大地形数据以瓦片金字塔形式存储于硬盘,绘制每一帧时只调度当前场景所需的少量瓦片进入显存。首先利用GPU实时计算地形网格点的地理坐标并传回CPU分析可见范围,然后采取瓦片四叉剖分、规则化处理和瓦片合并等一系列操作在所有LOD层中拣选最优瓦片集合并调入内存,在内存中利用一块固定大小的缓存进行管理与更新,并最终以单张纹理的形式传入显存进行采样和绘制。实验表明,该算法节约了大量的显存带宽,有效提升了系统在数据传输方面的执行效率,在大规模地形调度与绘制中取得了较好的效果。

关键词: 大规模地形绘制,动态调度,Virtual Texture,瓦片选取,瓦片管理,GPU

Abstract: Along with the development of the graphics hardware,the transmission of large-scale data has replaced the lack of rendering capacity as the new bottleneck of large scale terrain rendering.Aiming at this problem,we present a new approach for dynamic scheduling and real-time rendering for large-scale terrain.Terrain data are stored as tile-pyramid in hard disk,in real-time rendering phase,only a few of tiles are streamed into the video memory every frame.First,GPU computes and transfers geographic coordinates of the current scene into CPU in real time,CPU analyses and calculates the visible region through these coordinates,and then selects the optimum combination of visible tiles(visible tiles set) among all the layers by quad-tree generating,tiles regularization and tiles merging.The visible tiles set are streamed into CPU,managed and updated in a fix-sized buffer,and finally transferred into GPU as a texture for sampling and rendering.Experiments show that this algorithm saves a large amount of video memory bandwidth,improves the efficiency of data transmission effectively,and obtaines a good result in the large scale terrain scheduling and rendering.

Key words: Large-scale terrain rendering,Dynamic scheduling,Virtual texture,Tiles determination,Tiles management,GPU

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