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A Simple Physics Model to Animate Human Hair Modeled in 2D Strips in Real Time

  • Chuan Koon Koh
  • Zhiyong Huang
Part of the Eurographics book series (EUROGRAPH)

Abstract

This paper presents a simple Physics model to animate human hair modeled in 2D strips in real time. A major difficulty in animating human hair results from the large number of individual hair strands in a hairstyle. To address this problem, we have presented aframework of human hair modeling based on grouping hair strands into strips. Each hair strip is modeled by one patch of parametric surface. Polygon tessellation and the alpha-mapping using hair textures are then applied. To continue that work, we present a simple Physics model. In particular, a simple dynamic model is adapted and applied to the control point meshes. A set of dynamics equations are defined and solved. The parametric representation of hair strips can handle deformation of any complexity and still appear smooth. Moreover, because the number of control points is much smaller than that of the tessellated triangle vertices, the computation is fast and achieves real time animation. The animation of hair is controlled using event-triggered procedural animation primitives that implement wind, gravity as well as head movement. Inter hair strip collision avoidance is achieved by introducing springs between any two neighboring hair strips. Collision detection and avoidance of hair with other objects is implemented using ellipsoids and reaction constraints.

Keywords

Hair animation Physically-based modeling 

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References

  1. [Anjy92]
    [Anjy92]_K. Anjyo, Y. Usami, and T. Kurihura. A Simple Method For Extracting The Natural Beauty Of Hair, SIGGRAPH (92), pp. 111–120 (1992).Google Scholar
  2. [Böhm80]
    [Böhm80]_W. Böhm. Insert New Knots into B-spline Curves, Journal of Computer Aided Design, 12 (4), pp. 199–201 (1980).CrossRefGoogle Scholar
  3. [Chen99]
    [Chen99]_L. H. Chen, S. Saeyor, H. Dohi, and M. Ishizuka. A System of 3D Hair Style Synthesis Based on the Wisp Model, The Visual Computer, 15 (4), pp. 159–170 (1999).zbMATHCrossRefGoogle Scholar
  4. [Cohe80]
    [Cohe80]_E. Cohen, T. Lyche, and R. Risenfeld. Discrete B-Splines and Subdivision Technique in Computer-Aided Geometric Design and Computer Graphics, CGIP, 14 (2), pp. 87–111 (1980).Google Scholar
  5. [Dald93]
    [Dald93]_A. Daldegan, T. Kurihara, N. Magnenat Thalmann, and D. Thalmann. An Integrated System for Modeling, Animating and Rendering Hair, Proc. Eurographics (93), Computer Graphics Forum, Vo1.12, No 3, pp.211–221 (1993).CrossRefGoogle Scholar
  6. [Koh00]
    [Koh00]_C. K. Koh and Z. Huang, Real-time Animation of Human Hair Modeled in Strips, In: Computer Animation and Simulation, Springer-Verlag, pp. 101–110 (2000).CrossRefGoogle Scholar
  7. [Kong99]
    [Kong99]_W. Kong and M. Nakajima. Visible Volume Buffer for Efficient Hair Expression and Shadow Generation, Computer Animation (99), IEEE Computer Society, pp. 58–65 (May 1999).Google Scholar
  8. [Kuri93]
    [Kuri93]_T. Kurihara, K. Anjyo, and D. Thalmann. Hair Animation with Collision Detection, Models and Techniques in Computer Animation (93), Springer-Verlag, Tokyo, pp. 128–138 (1993).Google Scholar
  9. [Meye91]
    [Meye91]_A. Meyer. A Linear Time Oslo Algorithm, TOG (10), pp. 312–318 (1991).zbMATHGoogle Scholar
  10. [Neyr98]
    [Neyr98]_F. Neyret. Modeling, Animating, and Rendering Complex Scenes Using Volumetric Textures, IEEE Transactions on Visualization and Computer Graphics, 4 (1), pp. 55–70 (January-March 1998).CrossRefGoogle Scholar
  11. [Plat88]
    [Plat88]_J. C. Platt and A. H. Barr. Constraint Methodsfor Flexible Models, SIGGRAPH (88), pp. 279–288 (1988).Google Scholar
  12. [Rose91]
    [Rose91]_R. E. Rosenblum, W E. Carlson, and I. E. Tripp. Simulating the Structure and DynamiCS of Human Hair: Modeling, Rendering and Animation. The Journal of Visualization and Computer Animation, 2 (4), pp. 141–148 (1991).CrossRefGoogle Scholar
  13. [Tann98]
    [Tann98]_C. C. Tanner, C. J. Migdal, and M. T. Jones. The Clipmap: A Virtual Mipmap, SIGGRAPH (98), pp. 151–158 (1998).Google Scholar
  14. [Terz88]
    [Terz88]_D. Terzopoulos and K. Fleischer, Deformable Models, The Visual Computer, 4 (6), pp. 306–33 (1998).CrossRefGoogle Scholar
  15. [Thal93]
    [Thal93]_N. Magnenat Thalmann and A. Daldegan. Creating Virtual Fur and Hair Styles for Synthetic Actors. In Communicating with Virtual Worlds, Springer-Verlag, Tokyo, pp. 358–370 (1993).CrossRefGoogle Scholar
  16. [Wata92]
    [Wata92]_Y. Watanabe and Y. Suenaga. A Trigonal Prism-Based Method For Hair Image Generation, IEEE CGA, 12 (1), pp. 47–53 (1992).Google Scholar

Copyright information

© Springer-Verlag Wien 2001

Authors and Affiliations

  • Chuan Koon Koh
    • 1
  • Zhiyong Huang
    • 1
  1. 1.Department of Computer ScienceSchool of Computing National University of SingaporeSingapore

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