大规模非结构网格上基于PC的流线可视化研究

RESEARCH ON PC-BASED STREAMLINE VISUALIZATION ON LARGE UNSTRUCTURED GRIDS

针对大规模非结构网格 ,提出了两种基于 PC的流线可视化方法 :内存映像文件方法 (MMFM)和多线程out- of- core方法 (MTOM) .利用八叉树空间划分大规模非结构网格 ,并讨论了数据块的组织结构 .MMFM将大规模数据文件映像成虚拟 RAM,流线构造与 in- core方法类似 ,利用空间分块组织数据 ,减少缺页请求 .MTOM利用多线程技术实现 out- of- core流线构造 ,使得 CPU和 I/ O重叠 ,隐藏时延 ,在多 CPU上还可并行处理 .测试结果表明 ,MMFM,MTOM都可利用较少内存进行大规模非结构网格的流线可视化 。

Presented in this paper are two PC based streamline visualization methods for large unstructured grids: the memory mapped file method (MMFM) and the multithread out of core method (MTOM). Large unstructured grids are spatially partitioned in an octree, and data structures are also discussed. MMFM constructs streamlines like in core methods through mapping large data file into virtual RAM, and reduces page faults by organizing data in spatial blocks. MTOM implements out of core streamline construction with multithread technology. MTOM can overlap CPU and I/O, and can process in parallel with multiple CPUs. The test results show that the MMFM or the MTOM can make streamline visualization on large unstructured grids with less memory, and has more efficient performance.