基于混合方法的柔性材料建模的研究与实现
摘要
柔性材料的大量应用，以及虚拟现实技术的蓬勃发展，迫切要求我们能对柔性物体，特别是布料等，和人紧密相关的柔性物体，在计算机上进行模拟。服装加工前就知道着装效果，对服装领域有着极为重要的作用。模拟穿着衣服的人以及放在台子上的衣料，并且将它和计算机辅助设计联系起来，已经得到了越来越多的研究。本文通过对柔性材料的建模及算法的研究，为人体模型及人体着装的进一步研究做出了积极而有效的贡献，得到了陕西省自然科学基金(000X002)的支持。
布料模型通常分为三种(1)几何模型(2)物理模型(3)混合模型。几何模型具有建模速度快的优点，但是不能产生精确的动态效果。物理模型可得到精确的动态效果，但比较耗时。目前的混合模型可以在几何和物理模型的基础上，在较短时间内达到动态的建模效果，但没有考虑到各个运动状态的连续型。因此，本文针对上述问题，从布料的组成，编织结构，受力情况，环境作用出发，充分考虑到布料的几何、物理(其中包括受力，能量)特性，并在此基础上对放置在桌面上的布料进行受力分析，运动分析、和能量分析。在此基础上进行实验，建模，并提出了一种自动的三角网格剖分算法，以及新的冲突检测算法。通过这项工作，基本解决了上述模型实时性差的问题。在微机上实现了对桌布的动态模拟，减少了运算时间。达到了动态模拟的精确性和实时性的统一。
With the slather application of flexible object, and the prosperous development of technique of virtual reality, it is important to modeling for the flexible object on the computers, especially the cloth that has close relation with people. It would have great effect for the clothing field if we know the appearance before the cloth was made. So, it has profound and lasting meaning for flexible and clothing industry to molding the cloth putted on the people or on the desk by computers. This paper makes great contribution to the further research of flexible objects through modeling the flexible material.
The model of simulating cloth usually has three kinds. (1) Geometric model (2) Physical model (3)Hybrid model. The geometric has the advantage of faster modeling, but it hard to attain the precision pattern which in order to add dynamic effect. The physical model can get dynamic effect, but it would consume great time. The present hybrid model could attain the dynamic effect in shorter time, but it does not consider the series of different motive states. To solve the above problems, this paper stated from the composites, fabric. It considers the properties such as geometric, physical and energy of the cloth, sufficiently. On this basis, it analysis, and model the cloth on a desk. Through this work, the problem of real time is mainly solved in computer. A new algorithm for the adaptive triangulation of Curved Surface and A new algorithm for the collision detecting and dealing with are putted forward. These algorithms decrease the consumed time in triangulation- curved surface. Advance union of precision and real time.
布料模型通常分为三种(1)几何模型(2)物理模型(3)混合模型。几何模型具有建模速度快的优点，但是不能产生精确的动态效果。物理模型可得到精确的动态效果，但比较耗时。目前的混合模型可以在几何和物理模型的基础上，在较短时间内达到动态的建模效果，但没有考虑到各个运动状态的连续型。因此，本文针对上述问题，从布料的组成，编织结构，受力情况，环境作用出发，充分考虑到布料的几何、物理(其中包括受力，能量)特性，并在此基础上对放置在桌面上的布料进行受力分析，运动分析、和能量分析。在此基础上进行实验，建模，并提出了一种自动的三角网格剖分算法，以及新的冲突检测算法。通过这项工作，基本解决了上述模型实时性差的问题。在微机上实现了对桌布的动态模拟，减少了运算时间。达到了动态模拟的精确性和实时性的统一。
With the slather application of flexible object, and the prosperous development of technique of virtual reality, it is important to modeling for the flexible object on the computers, especially the cloth that has close relation with people. It would have great effect for the clothing field if we know the appearance before the cloth was made. So, it has profound and lasting meaning for flexible and clothing industry to molding the cloth putted on the people or on the desk by computers. This paper makes great contribution to the further research of flexible objects through modeling the flexible material.
The model of simulating cloth usually has three kinds. (1) Geometric model (2) Physical model (3)Hybrid model. The geometric has the advantage of faster modeling, but it hard to attain the precision pattern which in order to add dynamic effect. The physical model can get dynamic effect, but it would consume great time. The present hybrid model could attain the dynamic effect in shorter time, but it does not consider the series of different motive states. To solve the above problems, this paper stated from the composites, fabric. It considers the properties such as geometric, physical and energy of the cloth, sufficiently. On this basis, it analysis, and model the cloth on a desk. Through this work, the problem of real time is mainly solved in computer. A new algorithm for the adaptive triangulation of Curved Surface and A new algorithm for the collision detecting and dealing with are putted forward. These algorithms decrease the consumed time in triangulation- curved surface. Advance union of precision and real time.
引文
[1] I.L.Rudomin, "Simulating Cloth using a Mixed Geometry-Physical Method", doctoral dissertation, Dept. of Computer and Information Science, Univ of Pennsylvania, 1990
[2] T.L.Kunni and H.Gotoda. "Singularity Theoretical Modeling and Animation of Garment Wrinkle Formation Process" Visual Computer, Vol.6, 1990, pp.326-336．
[3] F.Taillefer, "Mixed Modeling," Proc. Computer Graphics 1991, pp.467-478．
[4] H.Ng and R.L.Gramsale, "GEOFF-A Geometrical Editor for Fold Formation," Lecture Notes in Computer Science Vol.1024: Image Analysis Applications and Computer Graphics, R.Chin et al, Springer-Verlag, Berlin, 1995, pp. 124-131．
[5] H.Ng, "Fast Techniques for the Modeling and Visualization of Cloth," doctoral Dissertation, Center for VLSI and Computer Graphics, University of Sussex, UK, may 1996．
[6] C.Feynman, "Modeling the Apperence of Cloth," master's thesis. Dept. of EEcs, Massachusetts Inst. of Technology, Cambrige, Mass., 1986．
[7] T.L.Kunii and H.Gotoda, "Singularity Theoretical Modeling and Animation of Garment Wrinkle Formation Process," Visual Computer, Vol.6, No.6, 1990, pp.326-336．
[8] C.Feynman, "Modeling the Appearance of Cloth" Computer Garaphics, Vol 9, No.13,1991,pp.213-219．
[9] D.Terzopoulos et al., "Elastically Deformable Models," Computer Graphics, Vol.21, No.4, July 1987, pp.205-214．
[10] D.E.Breen, "A Partical-Based Model for Simulating the Draping Behavior of Woven Cloth," Computer Graphics, Vol 15, No 7, March 1987, pp.182-196．
[11] J.Weil, "The Synthesis of Cloth Objects," Computer Graphics, (Proc.Siggraph), Vol 20,1986,pp.49-54．
[12] Anglada Marc Vigo. "An Improved Increamental Algorithm for Constructing Restricted Delaunay Tringulations." Computer &Graphics, Vol.21, No.2, 1997, pp.215-233．
[13] D.Terzopoulos, J.C.Platt, and A.H.Barr. "Elastically deformable models. " Computer Graphics, No 21 1987, pp.205-214．
[14] D.Terzopoulos and K.Fleischer. "Modeling inelastic deformation: Viscoelastictiy, Plasticity, Fracture," Computer Graphics, Vol.22 ACM, August 1988, pp.269-278.
[15] M.Carignan, Y. Yang, N.Magenent-Thamann, and D.Thalmann, "Dressing animated systhetic actors with complex deformable clothes." Computer Graphics (Proc.Siggraph) 1992, pp.99-104.
[16] P. Volino, M.Courchesne, and N.Magnenat Thamann. "Versatile and efficient techniques for simulating cloth and other deformable objects" Computer Graphics (Proc. Siggraph) 1995, pp. 137-144.
[17] D.E.Breen, D.H.House, and M.J.Wozny. "Predicting the drape of woven cloth using interacting particles." Computer Graphics (Proc. Siggraph), 1994, pp.363-372.
[18] B.Eberhardt, A.Weber, and W. Stasser. "A Fast, Flexible, Partical-System Model for Cloth Draping." IEEE Computer Graphics and Applications, No16, 1996, pp.52-59.
[19] 白建军 朱亚萍等《Open GL三维图形设计与制作》人民邮电出版社1999年5月。
[20] D. Baraff and A. Witkin: "Large Steps in Cloth Simulation." Computer Graphics. (Proc SIGGRAPH)pp. 43-54, 1998
[21] 何世明《Open GL编程与实例》电子工业出版社 1999年1月。pp．4-80, 117-172．
[22] 何淑芷《数学物理方法》华南理工大学出版社 1994，8月
[23] 漆安慎 杜婵英《力学》高等教育出版社1997年7月，pp．88-90，335-338．
[24] D. Hearn M.P.baker "Computer Graphics" 蔡士杰 吴春镕等译《计算机图形学》，电子工业出版社，1998年4月．
[25] 蒋孝煜《有限元法基础》清华大学出版社，1992，pp167-172，182-192，185-188．
[26] 梁昆淼，《力学》(下册，第三版)，高等教育出版社，1992，pp．326-336．
[27] 漆安慎 杜婵英《力学基础》高等教育出版社 1982年12月，pp．165-174，191-198．
[28] 李庆扬、王能超、易大义《数值分析》，华中理工大学出版社，1986，pp．154-163．
[29] M. Desbrun, P. Schrder and A. Barr. "Interactive Animation of Structured Deformable Objects". In Graphics Interface'99. June 1999.
[30] 贾晓峰 石冰《微积分与数学模型》高等教育出版社，施普林格出版社1999
年8月 , pp.326-33．
[31] J.Nisselson, "Computer Graphics and the Fashion Industry", Proc. of Graphics Interface, 1986, pp. 1-6．
[32] J.Nisselson, "Computer Graphics in Fashion", Computer Graphics (Proc siggraph), Vol. 21, No.4, July 1987,pp 333-334． .
[33] M.Aono, "A Wrinkle Propagation Model for Cloth" Proc CG Int'l Springer-Verlag Berlin, 1990, pp. 95-115．
[34] N.M-Thalmanns and Y.Yang "Techniques for animation" in New Trend in animation and visualization N.M-Thalmanns and D. Thalmanns eds, John Weley & Sons UK 1991, pp.243-256．
[35] J.eff Lander. "Devil in the Blue-Faceted Dress: Real-time Cloth Animation", in Game Developer Magazine. May 1999．
[36] G.Anderson, "A Particle Based Model of Draping Behavior of Woven Cloth", internal report,Edinburgh Parallel Computer Center, Univ. of Edinburgh, UK, Sept 1993．
[2] T.L.Kunni and H.Gotoda. "Singularity Theoretical Modeling and Animation of Garment Wrinkle Formation Process" Visual Computer, Vol.6, 1990, pp.326-336．
[3] F.Taillefer, "Mixed Modeling," Proc. Computer Graphics 1991, pp.467-478．
[4] H.Ng and R.L.Gramsale, "GEOFF-A Geometrical Editor for Fold Formation," Lecture Notes in Computer Science Vol.1024: Image Analysis Applications and Computer Graphics, R.Chin et al, Springer-Verlag, Berlin, 1995, pp. 124-131．
[5] H.Ng, "Fast Techniques for the Modeling and Visualization of Cloth," doctoral Dissertation, Center for VLSI and Computer Graphics, University of Sussex, UK, may 1996．
[6] C.Feynman, "Modeling the Apperence of Cloth," master's thesis. Dept. of EEcs, Massachusetts Inst. of Technology, Cambrige, Mass., 1986．
[7] T.L.Kunii and H.Gotoda, "Singularity Theoretical Modeling and Animation of Garment Wrinkle Formation Process," Visual Computer, Vol.6, No.6, 1990, pp.326-336．
[8] C.Feynman, "Modeling the Appearance of Cloth" Computer Garaphics, Vol 9, No.13,1991,pp.213-219．
[9] D.Terzopoulos et al., "Elastically Deformable Models," Computer Graphics, Vol.21, No.4, July 1987, pp.205-214．
[10] D.E.Breen, "A Partical-Based Model for Simulating the Draping Behavior of Woven Cloth," Computer Graphics, Vol 15, No 7, March 1987, pp.182-196．
[11] J.Weil, "The Synthesis of Cloth Objects," Computer Graphics, (Proc.Siggraph), Vol 20,1986,pp.49-54．
[12] Anglada Marc Vigo. "An Improved Increamental Algorithm for Constructing Restricted Delaunay Tringulations." Computer &Graphics, Vol.21, No.2, 1997, pp.215-233．
[13] D.Terzopoulos, J.C.Platt, and A.H.Barr. "Elastically deformable models. " Computer Graphics, No 21 1987, pp.205-214．
[14] D.Terzopoulos and K.Fleischer. "Modeling inelastic deformation: Viscoelastictiy, Plasticity, Fracture," Computer Graphics, Vol.22 ACM, August 1988, pp.269-278.
[15] M.Carignan, Y. Yang, N.Magenent-Thamann, and D.Thalmann, "Dressing animated systhetic actors with complex deformable clothes." Computer Graphics (Proc.Siggraph) 1992, pp.99-104.
[16] P. Volino, M.Courchesne, and N.Magnenat Thamann. "Versatile and efficient techniques for simulating cloth and other deformable objects" Computer Graphics (Proc. Siggraph) 1995, pp. 137-144.
[17] D.E.Breen, D.H.House, and M.J.Wozny. "Predicting the drape of woven cloth using interacting particles." Computer Graphics (Proc. Siggraph), 1994, pp.363-372.
[18] B.Eberhardt, A.Weber, and W. Stasser. "A Fast, Flexible, Partical-System Model for Cloth Draping." IEEE Computer Graphics and Applications, No16, 1996, pp.52-59.
[19] 白建军 朱亚萍等《Open GL三维图形设计与制作》人民邮电出版社1999年5月。
[20] D. Baraff and A. Witkin: "Large Steps in Cloth Simulation." Computer Graphics. (Proc SIGGRAPH)pp. 43-54, 1998
[21] 何世明《Open GL编程与实例》电子工业出版社 1999年1月。pp．4-80, 117-172．
[22] 何淑芷《数学物理方法》华南理工大学出版社 1994，8月
[23] 漆安慎 杜婵英《力学》高等教育出版社1997年7月，pp．88-90，335-338．
[24] D. Hearn M.P.baker "Computer Graphics" 蔡士杰 吴春镕等译《计算机图形学》，电子工业出版社，1998年4月．
[25] 蒋孝煜《有限元法基础》清华大学出版社，1992，pp167-172，182-192，185-188．
[26] 梁昆淼，《力学》(下册，第三版)，高等教育出版社，1992，pp．326-336．
[27] 漆安慎 杜婵英《力学基础》高等教育出版社 1982年12月，pp．165-174，191-198．
[28] 李庆扬、王能超、易大义《数值分析》，华中理工大学出版社，1986，pp．154-163．
[29] M. Desbrun, P. Schrder and A. Barr. "Interactive Animation of Structured Deformable Objects". In Graphics Interface'99. June 1999.
[30] 贾晓峰 石冰《微积分与数学模型》高等教育出版社，施普林格出版社1999
年8月 , pp.326-33．
[31] J.Nisselson, "Computer Graphics and the Fashion Industry", Proc. of Graphics Interface, 1986, pp. 1-6．
[32] J.Nisselson, "Computer Graphics in Fashion", Computer Graphics (Proc siggraph), Vol. 21, No.4, July 1987,pp 333-334． .
[33] M.Aono, "A Wrinkle Propagation Model for Cloth" Proc CG Int'l Springer-Verlag Berlin, 1990, pp. 95-115．
[34] N.M-Thalmanns and Y.Yang "Techniques for animation" in New Trend in animation and visualization N.M-Thalmanns and D. Thalmanns eds, John Weley & Sons UK 1991, pp.243-256．
[35] J.eff Lander. "Devil in the Blue-Faceted Dress: Real-time Cloth Animation", in Game Developer Magazine. May 1999．
[36] G.Anderson, "A Particle Based Model of Draping Behavior of Woven Cloth", internal report,Edinburgh Parallel Computer Center, Univ. of Edinburgh, UK, Sept 1993．