室内虚拟环境构建研究
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摘要
作为虚拟战场环境的构成要素,室内虚拟环境的研究是战场环境仿真研究体系中不可或缺的组成部分。本文围绕构建一个实时、可进入、近真实的室内虚拟环境展开研究,其中,侧重解决实时绘制条件下的碰撞问题,并着重研究了室内漫游中的快速碰撞检测、碰撞响应、模型数据组织、场景数据调度以及室内光影计算等几个问题。
本文的研究工作主要体现在以下几个方面:
1.通过总结现有碰撞检测算法,提出了利用图像深度检测的方法来简化室内虚拟环境中的碰撞检测;实现了基于OpenGL拾取技术的快速碰撞检测算法,使用物体空间的加速方法对其进行了优化,并通过实验验证了该算法的优越性。最后,结合射线求交技术,实现了室内虚拟环境中的地形跟随。
2.通过研究碰撞响应及相关物理模型,找出了影响碰撞响应求解的场景要素,为室内场景数据重组提供了理论上的依据,从而为室内虚拟环境面向仿真应用打下了基础;通过实现门对视点碰撞的响应(开闭),验证了模型数据组织的合理性。
3.为提高碰撞检测效率,保证绘制的实时性,针对建筑物室内场景的高度遮挡特征,构建了适合建筑物室内场景数据调度的建筑物/楼层/房间层次结构;提出了基于视点位置的数据调度方法,并验证了该方案的可行性。
4.针对室内场景特点,对光影效果模拟进行了尝试性探讨。提出使用局部光照模型和阴影算法相结合的方法来模拟场景光影。使用有约束条件的面法线向量求平均的方法计算模型顶点法向量,改进了光照渲染效果;采用阴影体技术为场景添加阴影,进一步增添了场景的真实感。
As a component of the virtual battlefield environment, it is indispensable to study virtual indoor environment in the simulation of the battlefield environment. This paper build a real-time rendering, immersing and near-real virtual indoor environment, focusing on some key technologies, such as rapid collision detection, collision response, data organization, scene data organization and scheduling as well as the calculation of lighting and shadow in indoor scene.
The following contents are what we have done in this dissertation:
1. By summarizing some common collision detection algorithms, we present a method to simplify collision intersection with image depth detection in indoor virtual environment. We implement a fast collision detection algorithm with OpenGL-based pick technology. And we also optimize the algorithm combining object space acceleration method. Finally we demonstrate its feasibility by experiment.Combining the radial intersection technology, we implement the terrain following in virtual indoor environment.
2. By a research on collision response and its physical models, we find out the key elements that affect the collision response. It provides theoretic accordance for the model data reorganization, and is also the foundation of the application of the indoor environment simulation. And we implement the door's response to viewpoint collision (on and off) and validate the rationality of reorganization.
3. Based on the high hidden attribute of the indoor environment, we design a hierarchical structure of buildings, floors and rooms to meet the need of real-time data requirement and present a method of data scheduling based on viewpoint position. At last, we validate its feasibility by experiment.
4. We try to explore ways to improve the scene reality considering the characteristics of indoor environment. For example, we improve the light rendering effect with the method of getting the vertexes' normals by the mean value of the faces' that satisfied the constrained condition; and we perfect the scene vision by using shadow volume technology to render shadows in the scene.
本文的研究工作主要体现在以下几个方面:
1.通过总结现有碰撞检测算法,提出了利用图像深度检测的方法来简化室内虚拟环境中的碰撞检测;实现了基于OpenGL拾取技术的快速碰撞检测算法,使用物体空间的加速方法对其进行了优化,并通过实验验证了该算法的优越性。最后,结合射线求交技术,实现了室内虚拟环境中的地形跟随。
2.通过研究碰撞响应及相关物理模型,找出了影响碰撞响应求解的场景要素,为室内场景数据重组提供了理论上的依据,从而为室内虚拟环境面向仿真应用打下了基础;通过实现门对视点碰撞的响应(开闭),验证了模型数据组织的合理性。
3.为提高碰撞检测效率,保证绘制的实时性,针对建筑物室内场景的高度遮挡特征,构建了适合建筑物室内场景数据调度的建筑物/楼层/房间层次结构;提出了基于视点位置的数据调度方法,并验证了该方案的可行性。
4.针对室内场景特点,对光影效果模拟进行了尝试性探讨。提出使用局部光照模型和阴影算法相结合的方法来模拟场景光影。使用有约束条件的面法线向量求平均的方法计算模型顶点法向量,改进了光照渲染效果;采用阴影体技术为场景添加阴影,进一步增添了场景的真实感。
As a component of the virtual battlefield environment, it is indispensable to study virtual indoor environment in the simulation of the battlefield environment. This paper build a real-time rendering, immersing and near-real virtual indoor environment, focusing on some key technologies, such as rapid collision detection, collision response, data organization, scene data organization and scheduling as well as the calculation of lighting and shadow in indoor scene.
The following contents are what we have done in this dissertation:
1. By summarizing some common collision detection algorithms, we present a method to simplify collision intersection with image depth detection in indoor virtual environment. We implement a fast collision detection algorithm with OpenGL-based pick technology. And we also optimize the algorithm combining object space acceleration method. Finally we demonstrate its feasibility by experiment.Combining the radial intersection technology, we implement the terrain following in virtual indoor environment.
2. By a research on collision response and its physical models, we find out the key elements that affect the collision response. It provides theoretic accordance for the model data reorganization, and is also the foundation of the application of the indoor environment simulation. And we implement the door's response to viewpoint collision (on and off) and validate the rationality of reorganization.
3. Based on the high hidden attribute of the indoor environment, we design a hierarchical structure of buildings, floors and rooms to meet the need of real-time data requirement and present a method of data scheduling based on viewpoint position. At last, we validate its feasibility by experiment.
4. We try to explore ways to improve the scene reality considering the characteristics of indoor environment. For example, we improve the light rendering effect with the method of getting the vertexes' normals by the mean value of the faces' that satisfied the constrained condition; and we perfect the scene vision by using shadow volume technology to render shadows in the scene.
引文
[01]游雄等.战场环境仿真[M].郑州:中国人民解放军信息工程大学教材.2007.
[02]中国军队须高度重视城市战研究.http://www.china.com.cn/military/txt/2008-01/15/content-9534439.htm.
[03]刘强.建筑物室内模型三维数据管理及可见性算法研究[D].武汉:武汉大学,2002.
[04]魏迎梅.虚拟环境中碰撞检测问题的研究[D].长沙:国防科学技术大学,2000.
[05]王志强,洪嘉振,杨辉.碰撞检测问题研究综述[J].软件学报,1999,10(5):545-551.
[06]Jimenez P,Thomas F,Torras C.Collision detection:a survey[J],Computers and Graphics,2001,25(2):269-285.
[07]Samet H.Spatial data structures:quadtree,octrees and other hierarchical methods[D],Addison Wesley,1989,23-27.
[08]Naylor BF.Amanatides JA,Thibault WC.Merging BSP trees yield polyhedral modeling results[C].In Proceedings of ACM SIGGRAPH,1990,115-124.
[09]McNeely W,Puterbaugh K,Troy J.Six degree-of-freedom haptic rendering using voxel sampling[C].In Proceedings of Siggraph 1999,401-408.
[10]Hubbard.P.M.Approximating polyhedra with spheres for tune critical collision detection[J].ACM Transactions on Graphics,1996,15(3):179-210.
[11]Van Den Bergen.Efficient collision detection of complex defortnable models using AABB trees[J].Journal of Graphics Tools,1997,2(4):1-13.
[12]Gottschalk S,Lin.MC,Manocha.D.OBB Tree:a hierarchical structure for rapid interference detection[C],In ACM SIGGRAPH:SIGGRAPH 96 Conference Proceedings,New Orleans,USA,1996:171-180.
[13]James T.Klosowski.Efficient Collision Detection Using Bounding Volume Hierarchies of k-Dops[J],IEEE Transactions on Visualization and Computer Graphics,Vol.4 No.1,1998:26-27.
[14]魏迎梅,吴泉源,石教英.碰撞检测中的固定方向凸壳包围盒的研究[J],软件学报,2001,12(7):105-109.
[15]Ehmann S,Lin M C.Accurate and fast proximity queries between polyhedra using convex surface decomposition[C].In Proceedings of the Eurographics Conference,Manchester,2001:500-510.
[16]Shinya M,Forgue M.Interference detection through rasterization[J].Journal of Visualization and Computer Animation,1991,2:131-134.
[17]Rossignac J,Megahed A,Schneider BO.Interactive inspection of solids:cross-section and interferences[J].Computer Graphics,1992,26(2):353-360.
[18]Myszkowski K,Okunev OG,Kunii TL.Fast collision detection between computer solids using rasterizing graphics hardware[J],The Visual Computer,1995,11:497-511.
[19]Baciu G,Wong WSK.Rendering in object interference detection on conventional graphics workstations[C].In Proceedings of the Pacific Graphics,Seoul National University,Korea,October 1997:51-58.
[20]Baciu G,Wong SKW,Sun H.RECODE:An image-based collision detection algorithm[J],Journal of Visualization and Computer Animation,1999,10(4):181-192.
[21]Hoff KE,Zaferakis A,Lin M,Manocha D.Fast 3D geometric proximity queries between rigid&deformable models using graphics hardware acceleration,points at which edges intersect objects[R].North Carolina:Dept.of Computer Science,University of North Carolina,2002.
[22]Kim YJ,Lin M,Manocha D.Fast penetration depth estimation using rasterization hardware and hierarchical refinement[C].In Symposium on Computational Geometry'2003,2003:386-387.
[23]葛翔.基于OpenGL的三维建筑仿真与漫游技术研究[D].武汉:武汉理工大学,2006.
[24]常鑫.三维图形引擎中场景管理的研究与实现[D].成都:成都电子科技大学,2006,50-63.
[25]马登武,孙隆和,佟明安.虚拟场景中的碰撞检测算法[J].火力与指挥控制,2004,29(4):46-48.
[26]Gottschalk.S.Collision Queries using Oriented Bounding Box[D].N.Carolina:University of N.Carolina,2000:41-47.
[27]高丽娜,马尧海.虚拟漫游中的碰撞检测问题的解决方法[J].计算机仿真,2006,23(2):189-191.
[28]Richard S.Wright,Jr.Benjamin Lipchak.OpenGL超级宝典(第三版)[M].北京:人民邮电出版社,2005.
[29]Dave Shreiner,Mason Woo,Jackie Neider,Tom Davis.OpenGL编程指南(第四版)[M].北京:人民邮电出版社,2005.
[30]周杨,徐青,肖勇辉.基于Z_buffer值的碰撞检测算法研究[J].计算机工程,2007,12(33):214-216.
[31]David M.Bourg.游戏开发物理学[M].北京:电子工业出版社,2004:93-103
[32]林春屹.融合物理特性的3D图形引擎技术研究[D].重庆:重庆大学,2006.
[33]康颖.大学物理(上册)[M].北京:科学出版社,2006:70-123.
[34]刘桂秋.砌体结构基本受力性能的研究[D].湖南:湖南大学,2005,6-7.
[35]李磊.场景快速渲染中的入口生成技术研究[D].浙江:浙江大学,2006.
[36]Tomas Akenine-Moller,Eric Haines.实时计算机图形学[M].北京:北京大学出版社,2004:40-67.
[37]沈潇.三维场景实时阴影算法的研究与实现[D].重庆:重庆大学,2006:18-25.
[38]程剑.实时动态阴影的研究及实现[D].浙江:浙江大学,2005:6-20.
[39]和平鸽工作室.OpenGL三维图形系统开发与实用技术(实用技术篇)[M].北京:清华大学出版社,2003:2-8.
[40]Wan HG,Fan ZW,Gao SM,Peng QS.A parallel collision detection algorithm based on hybrid bounding volume hierarchy[C],in Proceedings of CAD&Graphics' 2001,Kunming,China,2001:521-528.
[41]David.H.Eberly.3D Game Engine Design[M].San Francisco:Mogan Kaufmann Publishers,2001:79-138,359-404.
[42]M.Moore,J.Wilhelms.Collision Detection and response for computer animation[J].ACM Computer Graphics,1988,22(4):289-298.
[43]D.Baraff.Interactive simulation of solid rigid bodies[J].IEEE Computer Graphics and Applications,1995,15(3):63-75.
[44]D.Baraff.Fast contact force computation for nonpenetrating rigid bodies[J].ACM Computer Graphics,1994,28(1):23-34.
[45]V.Kamat.A survey of techniques for simulation of dynamic collision detection and response[J].Computer&Graphics,1993,17(4):379-385.
[46]J.M.Snyder.An interactive tool for placing curved surfaces without interpenetration[J].ACM Computer Graphics,1995,29(4):209-218.
[47]Alan Watt,Fabio Policarpo.3D游戏卷1实施渲染与软件技术[M].北京:机械工业出版社,2005.
[48]马登武,叶文,李瑛,吕晓峰.适用于复杂场景的碰撞检测算法研究[J].计算机仿真,2006:23(12).
[49]熊伟,毛善君,马蔼乃.基于观察者的碰撞检测技术在虚拟环境漫游中的应用[J].算机应用,2002,22(11).
[50]王剑,陆国栋,谭建荣.三维场景中图形对象的拾取方法[J].机械,2004,31(7).
[51]张唯,刘修国.三维场景漫游中碰撞检测问题的研究与实现[J].计算机工程与应用,2005.
[52]涂超.虚拟空间中的碰撞检测[J].武汉理工大学学报,2001,23(11).
[53]Gino van den Bergen.Collision Detection in Interactive 3D Environments[J].Morgan Kaufinann Publishers,2004.
[02]中国军队须高度重视城市战研究.http://www.china.com.cn/military/txt/2008-01/15/content-9534439.htm.
[03]刘强.建筑物室内模型三维数据管理及可见性算法研究[D].武汉:武汉大学,2002.
[04]魏迎梅.虚拟环境中碰撞检测问题的研究[D].长沙:国防科学技术大学,2000.
[05]王志强,洪嘉振,杨辉.碰撞检测问题研究综述[J].软件学报,1999,10(5):545-551.
[06]Jimenez P,Thomas F,Torras C.Collision detection:a survey[J],Computers and Graphics,2001,25(2):269-285.
[07]Samet H.Spatial data structures:quadtree,octrees and other hierarchical methods[D],Addison Wesley,1989,23-27.
[08]Naylor BF.Amanatides JA,Thibault WC.Merging BSP trees yield polyhedral modeling results[C].In Proceedings of ACM SIGGRAPH,1990,115-124.
[09]McNeely W,Puterbaugh K,Troy J.Six degree-of-freedom haptic rendering using voxel sampling[C].In Proceedings of Siggraph 1999,401-408.
[10]Hubbard.P.M.Approximating polyhedra with spheres for tune critical collision detection[J].ACM Transactions on Graphics,1996,15(3):179-210.
[11]Van Den Bergen.Efficient collision detection of complex defortnable models using AABB trees[J].Journal of Graphics Tools,1997,2(4):1-13.
[12]Gottschalk S,Lin.MC,Manocha.D.OBB Tree:a hierarchical structure for rapid interference detection[C],In ACM SIGGRAPH:SIGGRAPH 96 Conference Proceedings,New Orleans,USA,1996:171-180.
[13]James T.Klosowski.Efficient Collision Detection Using Bounding Volume Hierarchies of k-Dops[J],IEEE Transactions on Visualization and Computer Graphics,Vol.4 No.1,1998:26-27.
[14]魏迎梅,吴泉源,石教英.碰撞检测中的固定方向凸壳包围盒的研究[J],软件学报,2001,12(7):105-109.
[15]Ehmann S,Lin M C.Accurate and fast proximity queries between polyhedra using convex surface decomposition[C].In Proceedings of the Eurographics Conference,Manchester,2001:500-510.
[16]Shinya M,Forgue M.Interference detection through rasterization[J].Journal of Visualization and Computer Animation,1991,2:131-134.
[17]Rossignac J,Megahed A,Schneider BO.Interactive inspection of solids:cross-section and interferences[J].Computer Graphics,1992,26(2):353-360.
[18]Myszkowski K,Okunev OG,Kunii TL.Fast collision detection between computer solids using rasterizing graphics hardware[J],The Visual Computer,1995,11:497-511.
[19]Baciu G,Wong WSK.Rendering in object interference detection on conventional graphics workstations[C].In Proceedings of the Pacific Graphics,Seoul National University,Korea,October 1997:51-58.
[20]Baciu G,Wong SKW,Sun H.RECODE:An image-based collision detection algorithm[J],Journal of Visualization and Computer Animation,1999,10(4):181-192.
[21]Hoff KE,Zaferakis A,Lin M,Manocha D.Fast 3D geometric proximity queries between rigid&deformable models using graphics hardware acceleration,points at which edges intersect objects[R].North Carolina:Dept.of Computer Science,University of North Carolina,2002.
[22]Kim YJ,Lin M,Manocha D.Fast penetration depth estimation using rasterization hardware and hierarchical refinement[C].In Symposium on Computational Geometry'2003,2003:386-387.
[23]葛翔.基于OpenGL的三维建筑仿真与漫游技术研究[D].武汉:武汉理工大学,2006.
[24]常鑫.三维图形引擎中场景管理的研究与实现[D].成都:成都电子科技大学,2006,50-63.
[25]马登武,孙隆和,佟明安.虚拟场景中的碰撞检测算法[J].火力与指挥控制,2004,29(4):46-48.
[26]Gottschalk.S.Collision Queries using Oriented Bounding Box[D].N.Carolina:University of N.Carolina,2000:41-47.
[27]高丽娜,马尧海.虚拟漫游中的碰撞检测问题的解决方法[J].计算机仿真,2006,23(2):189-191.
[28]Richard S.Wright,Jr.Benjamin Lipchak.OpenGL超级宝典(第三版)[M].北京:人民邮电出版社,2005.
[29]Dave Shreiner,Mason Woo,Jackie Neider,Tom Davis.OpenGL编程指南(第四版)[M].北京:人民邮电出版社,2005.
[30]周杨,徐青,肖勇辉.基于Z_buffer值的碰撞检测算法研究[J].计算机工程,2007,12(33):214-216.
[31]David M.Bourg.游戏开发物理学[M].北京:电子工业出版社,2004:93-103
[32]林春屹.融合物理特性的3D图形引擎技术研究[D].重庆:重庆大学,2006.
[33]康颖.大学物理(上册)[M].北京:科学出版社,2006:70-123.
[34]刘桂秋.砌体结构基本受力性能的研究[D].湖南:湖南大学,2005,6-7.
[35]李磊.场景快速渲染中的入口生成技术研究[D].浙江:浙江大学,2006.
[36]Tomas Akenine-Moller,Eric Haines.实时计算机图形学[M].北京:北京大学出版社,2004:40-67.
[37]沈潇.三维场景实时阴影算法的研究与实现[D].重庆:重庆大学,2006:18-25.
[38]程剑.实时动态阴影的研究及实现[D].浙江:浙江大学,2005:6-20.
[39]和平鸽工作室.OpenGL三维图形系统开发与实用技术(实用技术篇)[M].北京:清华大学出版社,2003:2-8.
[40]Wan HG,Fan ZW,Gao SM,Peng QS.A parallel collision detection algorithm based on hybrid bounding volume hierarchy[C],in Proceedings of CAD&Graphics' 2001,Kunming,China,2001:521-528.
[41]David.H.Eberly.3D Game Engine Design[M].San Francisco:Mogan Kaufmann Publishers,2001:79-138,359-404.
[42]M.Moore,J.Wilhelms.Collision Detection and response for computer animation[J].ACM Computer Graphics,1988,22(4):289-298.
[43]D.Baraff.Interactive simulation of solid rigid bodies[J].IEEE Computer Graphics and Applications,1995,15(3):63-75.
[44]D.Baraff.Fast contact force computation for nonpenetrating rigid bodies[J].ACM Computer Graphics,1994,28(1):23-34.
[45]V.Kamat.A survey of techniques for simulation of dynamic collision detection and response[J].Computer&Graphics,1993,17(4):379-385.
[46]J.M.Snyder.An interactive tool for placing curved surfaces without interpenetration[J].ACM Computer Graphics,1995,29(4):209-218.
[47]Alan Watt,Fabio Policarpo.3D游戏卷1实施渲染与软件技术[M].北京:机械工业出版社,2005.
[48]马登武,叶文,李瑛,吕晓峰.适用于复杂场景的碰撞检测算法研究[J].计算机仿真,2006:23(12).
[49]熊伟,毛善君,马蔼乃.基于观察者的碰撞检测技术在虚拟环境漫游中的应用[J].算机应用,2002,22(11).
[50]王剑,陆国栋,谭建荣.三维场景中图形对象的拾取方法[J].机械,2004,31(7).
[51]张唯,刘修国.三维场景漫游中碰撞检测问题的研究与实现[J].计算机工程与应用,2005.
[52]涂超.虚拟空间中的碰撞检测[J].武汉理工大学学报,2001,23(11).
[53]Gino van den Bergen.Collision Detection in Interactive 3D Environments[J].Morgan Kaufinann Publishers,2004.