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1.
目前的碰撞检测方法大部分是基于简单的包围盒方法和简单的搜索算法的,这种算法精确度低且效率不高。基于凸分解与OBB层次结构的碰撞检测方法是对传统碰撞检测算法的一种改进,该方法继承了传统碰撞检测算法的优点,同时又对传统算法进行了必要的改进。实验证明,利用物体表面凸分解的方法解决了传统碰撞检测算法不能测试非凸物体相交的问题,拓宽了碰撞检测算法的应用范围;根据物体前后碰撞点的相关性,运用加速搜索提高了碰撞检测效率,降低了算法复杂度。  相似文献   

2.
目前的碰撞检测方法大部分是基于简单的包围盒方法和简单的搜索算法的,这种算法精确度低且效率不高。基于凸分解与OBB层次结构的碰撞检测方法是对传统碰撞检测算法的一种改进,该方法继承了传统碰撞检测算法的优点,同时又对传统算法进行了必要的改进。实验证明,利用物体表面凸分解的方法解决了传统碰撞检测算法不能测试非凸物体相交的问题,拓宽了碰撞检测算法的应用范围;根据物体前后碰撞点的相关性,运用加速搜索提高了碰撞检测效率,降低了算法复杂度。  相似文献   

3.
为了满足日益复杂的虚拟环境中碰撞检测的高实时性要求,提出一种基于图像空间的快速碰撞检测算法,有效利用了图形处理器(GPU)的加速功能。该算法以基于物体空间的凸块层次二叉树技术及方向包围盒(OBB)之间的碰撞检测为前提,可快速排除场景中明显不相交的凸块;然后通过生成的凸块潜在碰撞检测集,在RECODE算法的基础上,得到一种运行效率更高的碰撞检测算法。实验结果表明,在同等复杂的虚拟环境中,尤其是复杂度较高的虚拟环境中,该算法具有更高的碰撞检测实时性,取得了良好的效果。  相似文献   

4.
为了保证在大规模复杂场景中,碰撞检测的实时性和精确性,提出了一种基于图形空间与改进的图像空间相结合,并利用GPU加速的快速碰撞检测方法.利用AABB包围盒的检测策略,快速剔除不相交物体,确定潜在碰撞对象.改进传统的基于图像空间的碰撞检测算法,设计了基于向指定平面投影、模板测试和深度测试的碰撞检测算法.在此基础上,利用GPU的并行计算能力加速整个检测过程,有效地减少了碰撞检测时间.通过在虚拟驾驶系统当中的应用,验证了该方法在大规模复杂场景中碰撞检测的实时性和精确性.  相似文献   

5.
针对凸体间的连续碰撞检测,在距离算法(Gilbert-Johnson-Keerthi distance algorithm,GJK)基础上,提出一种采用运动轨迹分离轴计算的线性连续碰撞检测算法.该算法首先采用支撑点和投影技术,剔除必定不发生碰撞的物体,以加速碰撞检测的速度;然后,对可能发生碰撞的物体,计算2个凸体的Minkowski差集,所形成的凸包与运动路径执行GJK分离轴算法,实现在整个时间区间内一次性完成碰撞检测任务;最后,采用几何方法以及超平面与射线求解方式计算射线与凸体边界近交点,确定出第一次发生碰撞位置,并调整运动物体位置,完成碰撞响应过程.该算法不需要构造扫掠体,连续检测过程中不需要凸体间的求交计算.将文中算法应用于物体方向包围盒的连续碰撞检测,算法分析和实验结果表明,该算法对包围盒的连续碰撞检测具有较高检测精度和响应速度.  相似文献   

6.
基于启发式搜索分离向量的凸多面体碰撞检测   总被引:7,自引:0,他引:7  
碰撞检测是计算机模拟物理过程的基础,在计算机图形学、CAD/CAM、虚拟现实和机器人等领域有着广泛的应用.该文给出了一个新的用于凸多面体碰撞检测的算法——HP-jump.HP-jump建立了一个有效的碰撞检测模型用于报告物体的碰撞,同时提供了一个快速的启发式的策略用于搜索两个凸多面体的分离向量.该算法是利用凸多面体的层次表示来搜索支撑顶点对,用平衡二叉树来记录球面凸多边形的顶点,同时还利用了时间、空间相关性,这些都加速了算法的执行.该文的最后给出了HP-jump与GJK,I-COLLIDE算法的比较.  相似文献   

7.
为了实现对实体机器人逼真的模拟和准确的反馈,设计了一套具有一定通用性的机器人虚拟仿真系统,并在系统中对虚拟物体采用分类策略成功地将AABB与SWIFT++算法相结合,兼顾了仿真系统对碰撞检测算法的实时性与准确性的要求,有效地解决了效率与正确性之间的矛盾.在算法预处理阶段对非凸物体采用表面凸分解的方法,使碰撞检测算法具有处理非凸物体的能力.实验结果表明,该系统同样适用于服务型机器人,具有一定的通用性,碰撞检测算法比单独使用SWIFT++算法具有更快速的优点.  相似文献   

8.
针对如何提高碰撞检测算法实时性的问题,提出一种空间分解与层次包围盒相结合的碰撞检测算法,并利用物体运动的时空相关性来加速物体之间的碰撞检测速度。首先用空间分割的方法确定相邻物体,然后用基于时空相关性的层次包围盒方法检测物体之间的碰撞情况,在包围盒碰撞检测时采用加入预判的OBB相交测试方法,减少了包围盒的相交测试计算。实验结果表明,该算法能够实现多个物体同时发生碰撞的检测,并且提高碰撞检测的实时性。  相似文献   

9.
提出了一种基于最短距离计算的凸多面体碰撞检测算法。该算法利用凸多面体三维空间顶点坐标的凸包表示凸多面体,将两个凸多面体间碰撞检测问题归结为一个带约束条件的非线性规划问题,采用混合人工鱼群算法对该问题进行求解,寻优过程前期利用人工鱼群算法快速找到全局极值的邻域,后期切换到模式搜索法,准确找到全局极值。实验表明,无论在计算精度还是在计算速度方面,混合人工鱼群算法比惩罚函数法和遗传算法有更加明显的优势,能够满足碰撞检测的实时性和精确性的要求。  相似文献   

10.
目前高速、精确的碰撞检测研究已经成为虚拟现实领域研究的热点。在图像空间的碰撞检测研究基础上,设计了基于蜂窝状空间分解的碰撞检测算法。首先完成非碰撞多面体的快速剔除,对碰撞多面体局部进行空间分解,进而,反向投影构建碰撞模型局部子包围盒,完成沿相反方向进行子包围盒蜂窝状空间分解,将碰撞检测转化为判断在下一帧中多面体蜂窝子空间内局部子多面体截面到对方阈值线的距离值与对方所设定阈值大小的关系问题,完成任意多面体间的精细碰撞检测。摆脱了图形硬件信息存储的限制,也使基于图像空间的碰撞检测适用于任意多面体,提高了碰撞检测的速度和精度。  相似文献   

11.
The topological complexity of polygonal meshes has a large impact on the performance of various geometric processing algorithms, such as rendering and collision detection algorithms. Several approaches for simplifying topology have been discussed in the literature. These methods operate locally on models, which makes their effect on the topology hard to predict and analyze. Most existing methods tend to exhibit several disturbing artifacts, such as shrinking of the input and splitting of its components. We propose a novel top-down approach for topology simplification that avoids most problems that are common in existing methods. We start with a simple, genus-zero mesh that bounds the input and gradually introduce topologic features by a series of carving operations. This process yields a multiresolution stream of meshes with increasing topologic level of detail. We further present a carving algorithm that is based on constrained Delaunay tetrahedralization. The algorithm first constructs the tetrahedral mesh of the complement of the input with respect to its convex hull. It then proceeds to eliminate tetrahedra in a prioritized manner. We present quality results for two families of meshes that are difficult to simplify by all existing methods known to us: topologically complex meshes and highly clustered meshes.  相似文献   

12.
基于流的实时碰撞检测算法   总被引:21,自引:0,他引:21  
范昭炜  万华根  高曙明 《软件学报》2004,15(10):1505-1514
实时碰撞检测是计算机图形应用中不可或缺的问题之一,复杂物体间的实时碰撞检测至今仍未能得以很好的解决.高性能可编程图形硬件的出现,正在改变着通用计算仅能由CPU完成的传统观念.探索性地采用了可编程图形硬件来解决复杂物体间的实时碰撞检测问题.通过将两个任意物体间的碰撞检测计算映射到图形硬件以有效利用图形硬件的并行架构,由实时绘制过程快速产生碰撞检测结果.为此,算法首先将碰撞检测问题转化为一组线段集合与三角形的求交问题,以实现碰撞检测算法向可编程图形硬件的迁移.在对算法复杂度进行理性分析的基础上,给出了两种有效的优化技术以提升算法效率.实验结果表明,与现有的图像空间碰撞检测算法相比,该算法在效率、精确性和实用性方面具有明显优势.  相似文献   

13.
判断两个凸多面体是否相交的一个快速算法   总被引:14,自引:0,他引:14  
在机器人路径规划中,碰撞检测算法占有十分重要的地位.在智能机器人仿真系统中,碰撞检测耗用的时间在整个路径规划过程所用时间中占有相当大的比例.于是,如何进一步提高碰撞检测的速度在智能机器人路径规划系统中就起到了非常关键的作用.而碰撞检测问题最终转化为判断三维空间中两个凸多面体是否相交的问题.就这一问题,给出了一种新的算法,其思想是取一个从一个凸多面体指向另一个多面体的向量,根据两个多面体中的面与这一向量的相对位置关系来寻找相交的平面.即有两个多面体的交点位于这一平面,若能找到一个相交平面则可以断定两个多面体  相似文献   

14.
Fast and accurate collision detection between general polygonal models is a fundamental problem in physically based and geometric modeling, robotics, animation, and computer-simulated environments. Most earlier collision detection algorithms are either restricted to a class of models (such as convex polytopes) or are not fast enough for practical applications. The authors present an incremental algorithm for collision detection between general polygonal models in dynamic environments. The algorithm combines a hierarchical representation with incremental computation to rapidly detect collisions. It makes use of coherence between successive instances to efficiently determine the number of object features interacting. For each pair of objects, it tracks the closest features between them on their respective convex hulls. It detects the objects' penetration using pseudo internal Voronoi cells and constructs the penetration region, thus identifying the regions of contact on the convex hulls. The features associated with these regions are represented in a precomputed hierarchy. The algorithm uses a coherence based approach to quickly traverse the precomputed hierarchy and check for possible collisions between the features. They highlight its performance on different applications  相似文献   

15.
In this paper we address the problem of fast inclusion tests and distance calculation in very large models, an important issue in the context of environments involving haptic interaction or collision detection. Unfortunately, existing haptic rendering or collision detection toolkits cannot handle polygonal models obtained from 3D digitized point clouds unless the models are simplified up to a few thousand polygons, which leads to an important lack of detail for the scanned pieces. We propose a data structure that is able to manage very large polygonal models (over 25M polygons), and we explain how this can be used in order to compute the inclusion of a point into the solid surface very efficiently, performing several thousand point-in-solid tests per second. Our method uses a data structure called EBP-Octree (Extended Bounding-Planes Octree), which is a very tight hierarchy of convex bounding volumes. Based on a spatial decomposition of the model using an octree, at each node it defines a bounding volume using a subset of the planes of the portion of the polygonal model contained at that node. We use the EBP-Octree in a haptic interaction environment, where distance tests and the orientation of collided triangles must be accurate and fast. We also demonstrate that the proposed algorithm largely meets the interactive query rate demanded by a haptic interaction (1 kHz), despite being executed in a single CPU thread on a commonly available computer.  相似文献   

16.
近年来基于图象的绘制方法有了很大发展,其中光场方法提供了一种有效的四维参数化模型,但是这种四维函数局限于无遮挡的空间。为了在有遮挡的环境中运行,这种四维光场函数被扩展为五维光场函数,然而该方法在显示速度上仍达不到实时。采用基于狭缝图象的四维光场模型,以减少视点在垂直方向上的自由度为代价,使在有遮挡的环境中漫游速度大大加快。介绍了光场的表示、自适应非均匀采样、重采样的过程,并在内存管理、路径预测和碰撞检测等方面做了处理,使得在漫游过程中帧间图象过渡连续。最后以澳门科技大学学生活动中心为例,实现了三维漫游系统,漫游速度可以达到准实时。  相似文献   

17.
基于线性规划的碰撞检测算法研究   总被引:1,自引:1,他引:1  
介绍了虚拟环境中一种基于凸多面体面信息对偶线性规划模型(DualModel)的快速旋转和移动物体之间干涉碰撞实时检测方法。该文详细介绍了建模过程和求解步骤,物体由构成凸多面体的三角形面信息表示,而物体的运动由一组虚拟现实环境中的全局移动和旋转矩阵表示。这种数学编程方法具有数据结构简单、算法可靠和速度快等优点,同时能够很好地解决高速(运动帧)碰撞的问题。这一方法通过使用主-对偶(primal-dual)内点方法来解线性规划方程,具有很好的效果,能够检测多物体对之间的碰撞。实验结果表明,基于数学编程的方法相对两种著名的工具包I-COLLIDE和SOLID,具有速度快和稳定可靠的优点,而I-COLLIDE和SOLID工具包基于两种著名的算法:LinCanny(LC)最近特征算法和GJK算法(EnhancedGilbertJohnsonandKeethialgorithm)。  相似文献   

18.
A pseudo-triangulation is a planar subdivision into polygons with three convex vertices, useful for ray shooting, visibility problems and kinetic collision detection. As pseudo-triangulations are quite young, there is a lack of specialized algorithms for them. In this paper, we address the question of location in pseudo-triangulations. We propose two location algorithms based on the so-called stochastic walk and present their experimental results. The class of walk location algorithms is very popular for triangulations, namely in engineering applications, due to simplicity and low memory requirements, in spite of their non-optimality. As far as we know, no walk algorithm specialized on pseudo-triangulations has been developed before.  相似文献   

19.
Efficient collision detection using bounding volume hierarchies ofk-DOPs   总被引:1,自引:0,他引:1  
Collision detection is of paramount importance for many applications in computer graphics and visualization. Typically, the input to a collision detection algorithm is a large number of geometric objects comprising an environment, together with a set of objects moving within the environment. In addition to determining accurately the contacts that occur between pairs of objects, one needs also to do so at real-time rates. Applications such as haptic force feedback can require over 1000 collision queries per second. We develop and analyze a method, based on bounding-volume hierarchies, for efficient collision detection for objects moving within highly complex environments. Our choice of bounding volume is to use a discrete orientation polytope (k-DOP), a convex polytope whose facets are determined by halfspaces whose outward normals come from a small fixed set of k orientations. We compare a variety of methods for constructing hierarchies (BV-trees) of bounding k-DOPs. Further, we propose algorithms for maintaining an effective BV-tree of k-DOPs for moving objects, as they rotate, and for performing fast collision detection using BV-trees of the moving objects and of the environment. Our algorithms have been implemented and tested. We provide experimental evidence showing that our approach yields substantially faster collision detection than previous methods  相似文献   

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