基于显微CT扫描的三维织物仿真
|
摘要
基于体数据的三维织物仿真,是国内外计算机图形学界一个崭新的研究领域。体绘制就是依据三维体数据把获取的所有层次细节同时展现在二维图像上。采用体数掘进行织物仿真不仅能够反映出实际纱线表面复杂的捻度和毛羽效果,还能表现出纱线表面纤维的互相交叉、遮挡和半透明特性,而这些效果和特性是二维图像技术和三维面模型技术很难实现的。
论文介绍了国内外几种常见的织物仿真方法并进行了对比。首先提出了一种纱线体数据模型建立的新方法,然后建立了织物体数据模型,最后根据弹簧-质点模型实现了织物体模型的运动仿真。
论文的主要研究内容及贡献包括以下几个方面：
首先,建立单根纱线的体数据模型。组成体数据的每一个数据单位称之为体素。在本文中每个体素由R、 G、B、A四个数值组成,由显微CT扫描的纱线切片只可以获取纱线的密度信息即A值,而没有颜色信息。为了给纱线体数据模型赋上颜色,本文使用平板扫描仪扫描真实纱线,得到其彩色图像,采用一个迭代算法使显微CT扫描体数据投影图片的RGB值与平板扫描仪扫描纱线图像的RGB值的统计均值一致即可。
然后,建立整个织物的体数据模型。织物由多根纱线交织而成,纱线的中轴线采用三次B样条曲线来表示,根据织物结构中经纬线的中轴线位置信息对纱线体数据进行变换和填充,得到织物的体数据模型,利用体绘制方法进行绘制,得到真实感较强的仿真效果,可表现出纱线的毛羽、捻度等效果。
最后,实现织物体数据模型的运动仿真。以质点-弹簧模型为基础,结合经典的牛顿力学模型和运动学定律分析织物模型的受力情况,建立基于体数据织物模型的运动方程,给出了体数据模型中每个质点的位移量。每经过一个时间步长,更新一次中轴线的位置信息,再重建织物体数据模型,实现运动效果。
利用C++和OSG对上述方法进行了实验,实验结果表明基于体数据的织物仿真结果更加真实自然。
Simulation of Jacquard Fabrics based on volume data is a new direction of research in computer graphics field in recent years. The volume rendering technique is to show all the details at the same time on a two-dimensional image based on volume data. With this technology, it can reflect not only the complex twist and hairiness effect of yarn surface but also fibers crossing and translucent properties, which can not be achieved by other simulation methods such as two-dimensional image technology and three-dimensional surface modeling techniques.
The paper introduces several common fabric simulation methods and gives their comparisons. First of all, a new method is proposed to build volume data model of single yarn. Then a volume data model of fabric is established. Finally we simulate dynamic fabrics with volume data model based on the principles of mechanics.
The main research content and contribution includes the following aspects:
Firstly, a volume data model of single yarn is established. The unit data which composed of the whole volume data is called voxel. The four components in each voxel are R, G, B, A. But the yarn slice obtained by the micro-CT scan contains only A and does not contain R, G, and B. In order to obtain a color volume data model of yarn we use a flatbed scanner to scan real yarn. An iterative algorithm is being adopted to make the two statistics mean consistent.
Secondly, the volume data model of fabric is established. Multiple yarns interweave in fabric, and the central axis of yarn is represented by cubic B-spline curve. The final fabric volume model is refined by interpolating warped yarn data according to axis position of warp and weft yarns. The effects of hairiness and twist of yarns are manifested via volume rendering.
Finally, dynamic simulation of fabric volume model is achieved. Using the classic Newtonian mechanics model and the law of motion, we analyze the situation of the model based on the mass-spring model, and gives the composition and expression of internal and external forces of each particle in the volume model. The fabric volume model is dynamically simulated according to the position information of the central axis which is updated after each time step.
We implemented the algorithm using C++and OSG. Experimental results show that the model is feasible and the simulation results are natural.
论文介绍了国内外几种常见的织物仿真方法并进行了对比。首先提出了一种纱线体数据模型建立的新方法,然后建立了织物体数据模型,最后根据弹簧-质点模型实现了织物体模型的运动仿真。
论文的主要研究内容及贡献包括以下几个方面：
首先,建立单根纱线的体数据模型。组成体数据的每一个数据单位称之为体素。在本文中每个体素由R、 G、B、A四个数值组成,由显微CT扫描的纱线切片只可以获取纱线的密度信息即A值,而没有颜色信息。为了给纱线体数据模型赋上颜色,本文使用平板扫描仪扫描真实纱线,得到其彩色图像,采用一个迭代算法使显微CT扫描体数据投影图片的RGB值与平板扫描仪扫描纱线图像的RGB值的统计均值一致即可。
然后,建立整个织物的体数据模型。织物由多根纱线交织而成,纱线的中轴线采用三次B样条曲线来表示,根据织物结构中经纬线的中轴线位置信息对纱线体数据进行变换和填充,得到织物的体数据模型,利用体绘制方法进行绘制,得到真实感较强的仿真效果,可表现出纱线的毛羽、捻度等效果。
最后,实现织物体数据模型的运动仿真。以质点-弹簧模型为基础,结合经典的牛顿力学模型和运动学定律分析织物模型的受力情况,建立基于体数据织物模型的运动方程,给出了体数据模型中每个质点的位移量。每经过一个时间步长,更新一次中轴线的位置信息,再重建织物体数据模型,实现运动效果。
利用C++和OSG对上述方法进行了实验,实验结果表明基于体数据的织物仿真结果更加真实自然。
Simulation of Jacquard Fabrics based on volume data is a new direction of research in computer graphics field in recent years. The volume rendering technique is to show all the details at the same time on a two-dimensional image based on volume data. With this technology, it can reflect not only the complex twist and hairiness effect of yarn surface but also fibers crossing and translucent properties, which can not be achieved by other simulation methods such as two-dimensional image technology and three-dimensional surface modeling techniques.
The paper introduces several common fabric simulation methods and gives their comparisons. First of all, a new method is proposed to build volume data model of single yarn. Then a volume data model of fabric is established. Finally we simulate dynamic fabrics with volume data model based on the principles of mechanics.
The main research content and contribution includes the following aspects:
Firstly, a volume data model of single yarn is established. The unit data which composed of the whole volume data is called voxel. The four components in each voxel are R, G, B, A. But the yarn slice obtained by the micro-CT scan contains only A and does not contain R, G, and B. In order to obtain a color volume data model of yarn we use a flatbed scanner to scan real yarn. An iterative algorithm is being adopted to make the two statistics mean consistent.
Secondly, the volume data model of fabric is established. Multiple yarns interweave in fabric, and the central axis of yarn is represented by cubic B-spline curve. The final fabric volume model is refined by interpolating warped yarn data according to axis position of warp and weft yarns. The effects of hairiness and twist of yarns are manifested via volume rendering.
Finally, dynamic simulation of fabric volume model is achieved. Using the classic Newtonian mechanics model and the law of motion, we analyze the situation of the model based on the mass-spring model, and gives the composition and expression of internal and external forces of each particle in the volume model. The fabric volume model is dynamically simulated according to the position information of the central axis which is updated after each time step.
We implemented the algorithm using C++and OSG. Experimental results show that the model is feasible and the simulation results are natural.
引文
[1]诸葛振荣,吴佳.泊松方程在纱线仿真中的应用.浙江大学学报(工学版).2007,41(7)：1070-1072
[2]Hakan Ozdemir and Giingor Base. Computer simulation of woven structures based on actual yarn photographs. Computational Textile,2007,Volume 55/2007,75-91.
[3]王跃存,姜姗,熊途.光线跟踪算法在织物CAD中的应用.纺织学报,2007,28(8)：113-116.
[4]郑天勇,崔世忠.B样条曲面技术构建单纱模型的改进.纺织学报,2007,28(9)：35-40.
[5]张森林,姜位洪.织物计算机模拟设计的实现.纺织学报,2004,25(6)：81-84.
[6]Peter Shirley. Fundamentals of computer graphics, Second Edition. A K Peters, Ltd.,2005, p.561.
[7]Ying-Qing Xu, Yanyun Chen, Stephen Lin, Hua Zhong, Enhua Wu, Baining Guo, Heung-Yeung Shum. Photorealistic rendering of knitwear using the lumislice. Proceedings of SIGGRAPH 2001, Aug 12-17,2001, pp.391-398.
[8]Chen Yanyun, Stephen Lin, Hua Zhong,Ying-Qing Xu, Baining Guo and Heung-Yeung Shum. Realistic rendering and animation of knitwear. IEEE Transaction on Visualization and Computer Graphics,2003,9(1):43-55.
[9]Shuang Zhao, Wenzel Jakob, Steve Marschner,et al. Building Volumetric Appearance Models of Fabric using Micro CT Imaging.ACM Transactions of Graphics,30(4),44:1-44:10, August 2011.
[10]D Terzopoulos, J Platt, A Barr, K Fleischer. Elasitcally deformable models,1987. 205-214.
[11]D Chen, D Zeltzer. Pump it up:computer animation of a biomechanically based model of muscle using the finite element method,1992.89-98.
[12]L Nedel, D Thalmann. Real time muscle deformations using mass-spring systems, 1998.156-165.
[13]X.Provot. Deformation Constraints in a Mass-Spring Model to Describe Rigid Cloth Behavior. Proc. Graphics Interface.1995:147-154.
[14]J.A.Thingvold and E.Cohen. Physical modeling surfaces for interactive design. 1990:129.137.
[15]Breen, E. David, D.H.House and P.H.Geto. A physically Based Particle Model of Woven Cloth. The Visual Computer.1992,8(5-6):264-277.
[16]D.H. House, D.E.Breen and P.H.Getio. On the Dynamic Simulation of Physically-Based Particle-System Models. Third Eurographics Workshop on Animation and Simulation, Cambridge, England.1992,30.
[17]E.Grolier, R.T.Rau and W Strasser. Modeling and Visualization of Knitwear. IEEE Transactions on Visualization and Computer Graphics,1995.1(4):302-310.
[18]Eberhardt, Benrhard, A.Weber and W Strasser. A Fast.Flexible,Particle-System Model for Cloth Draping. IEEE Computer Graphics and Applications,1996,16(5):52-59.
[19]J.Plath. Realistic modeling of textile using interacting particle systems. Computers&Graphics 2001.24:897-905.
[20]Shuntaro Yamazaki, Masaaki Mochimaru, and Takeo Kanade,Inverse Volume Rendering Approach to 3D Reconstruction from Multiple Images,Lecture Notes in Computer Science. Heidelberg:Springer,2006, Volume 3851/2006,409-418
[21]Philippe Lacroute, Marc Levoy. Fast Volume Rendering Using a Shear-Warp Factorization of the Viewing Transformation,Computer Graphics Proceedings, Annual Conference Series, ACM SIGGRAPH.New York:ACM Press,1994:451-458
[22]Nielsen R, Keates R, et al. Weaving information file, version 1.1. http://www.mhsoft.com/wif/wif.html,1997.
[23]李胜,孟祥旭,屠长河.图案仿真在纹织CAD系统工艺自动化中的应用.第三届全球智能控制与自动化大会论文集.合肥：中国科学技术大学出版社,2000.2412-2416.
[24]吴奕立等.织物计算机模拟显示方法的探索.纺织学报.1999(5)：36-38.
[25]张彩明,杨兴强.李学庆等.计算机图形学.北京：科学出版社,2005：189-194.
[26]顾平.织物结构与设计学.上海,东华大学出版社,2006.
[27]Martin Sherbun. Geometric and Mechanical Modelling of Textiles. Nottingham: University of Nottingham,2007.
[28]Hivet G, Boisse P. Consistent 3D Geometrical Model of Fabric Elementary Cell:Application to a Meshing Preprocessor for 3D Finite Element Analysis. Finite Elements in Analysis and Design,2005,42(1):25-49.
[29]OpenSceneGraph[EB/OL].http://www.openscenegraph.org/projects/osg
[30]B.K.Hinds and J.McCarney. Interactive garment design. The Visual Computer, 1990,6(2):53-61.
[31]Ng H N, Grimsdale R L. GEOFF-a geometrical editor for fold formation. Image Analysis Applications and Computer Graphics. Springer Berlin Heidelberg,1995: 124-131.
[32]S.Hadap, E.Bangerter, P Volino and N. Magnenat-Thalmann. Animating Wrinkles on Clothes. Proceedings of the conference on Visualization'99 Celebrating ten years,1999:175-182.
[33]Kawabata S. The Standardization and Analys is of H and Evaluation(2nd edition)[M]. Japan:The Textile Machinery Society of Japan,1980.
[34]侯秀良,高卫东KES-F织物风格评价系统的发展.毛纺科技,2005(3)：46-48.
[35]Postle.R.Textile Asia,1989,(10):59.
[36]宁松,林木华,刘郊.一种快速的基于物理模型的织物模拟.计算机仿真,2006,12(23)：118-121.
[37]Jaruwan M, Ratan G, Shafaq C.3D Soft Body Simulation Using Mass-spring System with Internal Pressure Force and Simplified Implicit Integration. Journal of Computers.2007,2(8):34-43.
[38]褚莲娣.基于质点-弹簧模型的布模拟方法.嘉兴学院学报,2002,(5)：57-60.
[39]M.Oshita and A. Makinouchi. Real-Time Cloth Simulation with Sparse Particles and Curved Faces. In Proc. of Computer Animation 2001:220-227.
[40]李立康,於崇华,朱政华.微分方程数值解法.上海：复旦大学出版社,1999.
[41]Runge CD T. Uber die numerische Auflosung von Diferentialgleichungen. M-ath Ann,1985,78-821.
[42]施吉林,刘淑珍,陈桂芝.计算机数值方法.北京：高等教育出版社,1999.193-194.
[43]黄杏元,马劲松,汤勤.地理信息系统概论.北京：高等教育出版社,2001：93-103.
[44]邬伦,刘瑜,张晶,等.地理信息系统原理方法和应用.北京：科学出版社,2001：178-192.
[45]李新,程国栋,卢玲.空间内插方法比较.地球科学进展,2000,15(3)：260-265.
[2]Hakan Ozdemir and Giingor Base. Computer simulation of woven structures based on actual yarn photographs. Computational Textile,2007,Volume 55/2007,75-91.
[3]王跃存,姜姗,熊途.光线跟踪算法在织物CAD中的应用.纺织学报,2007,28(8)：113-116.
[4]郑天勇,崔世忠.B样条曲面技术构建单纱模型的改进.纺织学报,2007,28(9)：35-40.
[5]张森林,姜位洪.织物计算机模拟设计的实现.纺织学报,2004,25(6)：81-84.
[6]Peter Shirley. Fundamentals of computer graphics, Second Edition. A K Peters, Ltd.,2005, p.561.
[7]Ying-Qing Xu, Yanyun Chen, Stephen Lin, Hua Zhong, Enhua Wu, Baining Guo, Heung-Yeung Shum. Photorealistic rendering of knitwear using the lumislice. Proceedings of SIGGRAPH 2001, Aug 12-17,2001, pp.391-398.
[8]Chen Yanyun, Stephen Lin, Hua Zhong,Ying-Qing Xu, Baining Guo and Heung-Yeung Shum. Realistic rendering and animation of knitwear. IEEE Transaction on Visualization and Computer Graphics,2003,9(1):43-55.
[9]Shuang Zhao, Wenzel Jakob, Steve Marschner,et al. Building Volumetric Appearance Models of Fabric using Micro CT Imaging.ACM Transactions of Graphics,30(4),44:1-44:10, August 2011.
[10]D Terzopoulos, J Platt, A Barr, K Fleischer. Elasitcally deformable models,1987. 205-214.
[11]D Chen, D Zeltzer. Pump it up:computer animation of a biomechanically based model of muscle using the finite element method,1992.89-98.
[12]L Nedel, D Thalmann. Real time muscle deformations using mass-spring systems, 1998.156-165.
[13]X.Provot. Deformation Constraints in a Mass-Spring Model to Describe Rigid Cloth Behavior. Proc. Graphics Interface.1995:147-154.
[14]J.A.Thingvold and E.Cohen. Physical modeling surfaces for interactive design. 1990:129.137.
[15]Breen, E. David, D.H.House and P.H.Geto. A physically Based Particle Model of Woven Cloth. The Visual Computer.1992,8(5-6):264-277.
[16]D.H. House, D.E.Breen and P.H.Getio. On the Dynamic Simulation of Physically-Based Particle-System Models. Third Eurographics Workshop on Animation and Simulation, Cambridge, England.1992,30.
[17]E.Grolier, R.T.Rau and W Strasser. Modeling and Visualization of Knitwear. IEEE Transactions on Visualization and Computer Graphics,1995.1(4):302-310.
[18]Eberhardt, Benrhard, A.Weber and W Strasser. A Fast.Flexible,Particle-System Model for Cloth Draping. IEEE Computer Graphics and Applications,1996,16(5):52-59.
[19]J.Plath. Realistic modeling of textile using interacting particle systems. Computers&Graphics 2001.24:897-905.
[20]Shuntaro Yamazaki, Masaaki Mochimaru, and Takeo Kanade,Inverse Volume Rendering Approach to 3D Reconstruction from Multiple Images,Lecture Notes in Computer Science. Heidelberg:Springer,2006, Volume 3851/2006,409-418
[21]Philippe Lacroute, Marc Levoy. Fast Volume Rendering Using a Shear-Warp Factorization of the Viewing Transformation,Computer Graphics Proceedings, Annual Conference Series, ACM SIGGRAPH.New York:ACM Press,1994:451-458
[22]Nielsen R, Keates R, et al. Weaving information file, version 1.1. http://www.mhsoft.com/wif/wif.html,1997.
[23]李胜,孟祥旭,屠长河.图案仿真在纹织CAD系统工艺自动化中的应用.第三届全球智能控制与自动化大会论文集.合肥：中国科学技术大学出版社,2000.2412-2416.
[24]吴奕立等.织物计算机模拟显示方法的探索.纺织学报.1999(5)：36-38.
[25]张彩明,杨兴强.李学庆等.计算机图形学.北京：科学出版社,2005：189-194.
[26]顾平.织物结构与设计学.上海,东华大学出版社,2006.
[27]Martin Sherbun. Geometric and Mechanical Modelling of Textiles. Nottingham: University of Nottingham,2007.
[28]Hivet G, Boisse P. Consistent 3D Geometrical Model of Fabric Elementary Cell:Application to a Meshing Preprocessor for 3D Finite Element Analysis. Finite Elements in Analysis and Design,2005,42(1):25-49.
[29]OpenSceneGraph[EB/OL].http://www.openscenegraph.org/projects/osg
[30]B.K.Hinds and J.McCarney. Interactive garment design. The Visual Computer, 1990,6(2):53-61.
[31]Ng H N, Grimsdale R L. GEOFF-a geometrical editor for fold formation. Image Analysis Applications and Computer Graphics. Springer Berlin Heidelberg,1995: 124-131.
[32]S.Hadap, E.Bangerter, P Volino and N. Magnenat-Thalmann. Animating Wrinkles on Clothes. Proceedings of the conference on Visualization'99 Celebrating ten years,1999:175-182.
[33]Kawabata S. The Standardization and Analys is of H and Evaluation(2nd edition)[M]. Japan:The Textile Machinery Society of Japan,1980.
[34]侯秀良,高卫东KES-F织物风格评价系统的发展.毛纺科技,2005(3)：46-48.
[35]Postle.R.Textile Asia,1989,(10):59.
[36]宁松,林木华,刘郊.一种快速的基于物理模型的织物模拟.计算机仿真,2006,12(23)：118-121.
[37]Jaruwan M, Ratan G, Shafaq C.3D Soft Body Simulation Using Mass-spring System with Internal Pressure Force and Simplified Implicit Integration. Journal of Computers.2007,2(8):34-43.
[38]褚莲娣.基于质点-弹簧模型的布模拟方法.嘉兴学院学报,2002,(5)：57-60.
[39]M.Oshita and A. Makinouchi. Real-Time Cloth Simulation with Sparse Particles and Curved Faces. In Proc. of Computer Animation 2001:220-227.
[40]李立康,於崇华,朱政华.微分方程数值解法.上海：复旦大学出版社,1999.
[41]Runge CD T. Uber die numerische Auflosung von Diferentialgleichungen. M-ath Ann,1985,78-821.
[42]施吉林,刘淑珍,陈桂芝.计算机数值方法.北京：高等教育出版社,1999.193-194.
[43]黄杏元,马劲松,汤勤.地理信息系统概论.北京：高等教育出版社,2001：93-103.
[44]邬伦,刘瑜,张晶,等.地理信息系统原理方法和应用.北京：科学出版社,2001：178-192.
[45]李新,程国栋,卢玲.空间内插方法比较.地球科学进展,2000,15(3)：260-265.