基于OSG的虚拟现实碰撞检测及GPU并行加速.pdf

河北大学
硕士学位论文
基于OSG的虚拟现实碰撞检测及GPU并行加速
姓名:刘京
申请学位级别:硕士
专业:检测技术与自动化装置
指导教师:王洪瑞
2011-05
摘要
摘要
碰撞问题是机器人、动画仿真、虚拟现实、计算几何、CAD/CAM 等领域的关键问
题之一,而实时性和精确性是衡量一个碰撞检测算法是否优越的重要标准。尽管国内外
已经对碰撞检测问题做了许多有意义的工作,但是随着计算机软硬件及网络等技术的日
益成熟,尤其是 GPU 并行计算技术的快速发展,不同规模程度场景下实时而又精确的
碰撞检测问题逐步成为当前研究的热点。
针对大规模复杂场景的碰撞检测问题,本文首先从场景渲染入手,在详细了解 OSG
渲染引擎的场景组织方式、渲染流程之后,利用新一代的三维图形渲染系统的功能特性,
搭建一个高效的基于场景图的河北大学新校区校园漫游系统。进而在场景交互方面,通
过深入研究基于图像的碰撞检测算法,提出了实时性更好的基于向指定平面投影、模板
测试和深度测试的改进型图像空间碰撞检测算法,实现了虚拟校园漫游系统中对漫游角
色模型与场景模型之间的快速碰撞检测。同时引入 GPU 并行计算,调高了碰撞检测的
效率。
对于更加注重于碰撞检测精度的虚拟手术仿真系统来说,本文在基于距离的碰撞检
测算法基础之上,通过扫描线确定模型间潜在碰撞区域内的刨分顶点、自适应面刨分、
构造刨分三角形、判断刨分点到刨分三角形之间的距离实现了骨锯模型和头盖骨模型间
的精确碰撞检测。该算法不仅能获得碰撞发生位置,还把碰撞区域局限在几个刨分顶点
构成的多个刨分三角形之内,同时还继续引入 GPU 并行计算技术,优化了整个碰撞检
测算法,缩短了计算周期。

关键词:虚拟现实碰撞检测 OSG GPU 并行计算
I
Abstract
Abstract
Although many researchers had done much meaningful work about collision detection,
but along with puter software and hardware work technology fast developing,
especially the GPU puting technology, real-time and accurate collision detection
problem with the different scale scenes has became a hot issues.
For collision detection problems of large scale plicated scenes, we firstly
organized a virtual campus roaming scene of Hebei university using the function
characteristics of new 3d graphics rendering system after in detailed understanding the
organized way and rendering process of OSG rendering engine. Then through deeply studying
of the collision detection algorithm based on image, designing a improved based on image
collision detection with the designated planar projection, stencil test and depth test, realizing
the collision detection between roaming role model and scene models of the virtual campus
roaming system. Meanwhile introducing the GPU puting, improving the
efficiency of collision detection.
For the virtual surgery simulation which more focused on collision detection accuracy. In
this paper, after researched the collision algorit