Equivalence Principles Based Skin Deformation of Character Animation

  • You, L.H. (National Centre for Computer Animation, Bournemouth University) ;
  • Chaudhry, E. (National Centre for Computer Animation, Bournemouth University) ;
  • You, X.Y. (Faculty of Engineering and Computing, Coventry University) ;
  • Zhang, Jian J. (National Centre for Computer Animation, Bournemouth University)
  • Published : 2010.04.01

Abstract

Based on the equivalence principles of physical properties, geometric properties and externally applied forces between a surface and the corresponding curves, we present a fast physics and example based skin deformation method for character animation in this paper. The main idea is to represent the skin surface and its deformations with a group of curves whose computation incurs much less computing overheads than the direct surface-based approach. The geometric and physical properties together with externally applied forces of the curves are determined from those of the surface defined by these curves according to the equivalence principles between the surface and the curves. This ensures the curve-based approach is equivalent to the original problem. A fourth order ordinary differential equation is introduced to describe the deformations of the curves between two example skin shapes which relates geometric and physical properties and externally applied forces to shape changes of the curves. The skin deformation is determined from these deformed curves. Several examples are given in this paper to demonstrate the application of the method.

Keywords

References

  1. You, L.H., Chaudhry, E., You, X.Y. and Zhang, Jian J. (2009), Physics and example based skin deformations for character animation, In Proceedings of 11th IEEE International Conference on Computer-Aided Design and Computer Graphics, IEEE Press, 62-67.
  2. Thalmann, N.M., Laperriere, R. and Thalmann, D. (1988), Joint-dependent local deformations for hand animation and object grasping, In Proceedings of Graphics interface, 26-33.
  3. Lander, J. (May 1998), Skin them bones: Game programming for the web generation, Game Developer Magazine, 11-16.
  4. Lander, J. (October 1999), Over my dead, polygonal body, Game Developer Magazine,11-16.
  5. Weber, J. (2000), Run-time skin deformation, In Proceedings of Game Developers Conference.
  6. Wang, X.C. and Phillips, C. (2002), Multi-weight enveloping: least-squares approximation techniques for skin animation, In Proceedings of 2002 ACM SIGGRAPH/EUROGRAPHICS symposium on Computer animation, ACM Press, 129-138.
  7. Mohr, A. and Gleicher, M. (2003), Building efficient, accurate character skins from examples, ACM Transactions on Graphics 22(3), 562-568. https://doi.org/10.1145/882262.882308
  8. Kavan, L. and Zara, J. (2005), Spherical blend skinning: A real-time deformation of articulated models, In Proceedings of the 2005 Symposium on Interactive 3D Graphics and Games, 9-15.
  9. Yang, X.S., Somasekharan, A. and Zhang, J.J. (2006), Curve skeleton skinning for human and creature characters, Computer Animation and Virtual Worlds 17, 281-292. https://doi.org/10.1002/cav.132
  10. Lewis, L.P., Cordner, M. and Fong, N. (2000), Pose space deformation: a unified approach to shape interpolation and skeleton-driven deformation, In Proceedings of the 27th annual conference on Computer graphics and interactive techniques, ACM Press/Addison-Wesley Publishing Co., 165-172.
  11. Rhee, T., Lewis, J.P. and Neumann, U. (2006), Real-time weighted pose-space deformation on the GPU, Computer Graphics Forum 25(3), 439-448. https://doi.org/10.1111/j.1467-8659.2006.00963.x
  12. Mohr, A. and Gleicher, M. (2003), Building efficient, accurate character skins from examples, ACM Transactions on Graphics (SIGGRAPH 03) 22(3), 562-568. https://doi.org/10.1145/882262.882308
  13. Allen, B., Curless, B. and Popovi, Z. (2002), Articulated body deformation from range scan data, In Proceedings of the 2002 Conference on Computer Graphics (SIGGRAPH 02), ACM Press, 612-619.
  14. Kurihara, T. and Miyata, N. (2004), Modeling deformable human hands from medical images, In Proceedings of the 2004 ACM SIGGRAPH/Eurographics symposium on Computer animation, Eurographics Association, 355-363.
  15. Weber, O., Sorkine, O., Lipman, Y. and Gotsman, C. (2007), Context-aware skeletal shape deformation, Computer Graphics Forum 26(3), 265-274. https://doi.org/10.1111/j.1467-8659.2007.01048.x
  16. Scheepers, F.R., Parent, E., Carlson, W.E. and May, S.F. (1997), Anatomy-based modelling of the human musculature, In Proceedings of the 24th Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH 97), ACM Press/Addison-Wesley Publishing Co., 163-172.
  17. Jane, W. and Allen, V.G. (1997), Anatomically based modelling, In Proceedings of the 1997 Conference on Computer Graphics and Interactive Techniques (SIGGRAPH 97), ACM Press, 173-180.
  18. Nedel, L. and Thalmann, D. (1998), Modeling and deformation of human body using an anatomically-based approach, In Proceedings of the Computer Animation, IEEE Computer Society, 34-40.
  19. Nedel, L. and Thalmann, D. (2000), Anatomic modelling of deformable human bodies, The Visual Computer 16, 306-321. https://doi.org/10.1007/PL00007212
  20. Aubel, A. and Thalmann, D. (2001), Interactive modelling of the human musculature, In Proceedings of Computer Animation, Institute of Electrical and Electronics Engineers Inc., 167-173.
  21. Maryann, S., Jane, W., Allen, V.G. (2002), Model-based reconstruction for creature animation, In Conference Proceedings on ASM SIGGRAPH Symposium on Computer Animation, Institute of Electrical and Electronics Engineers Inc., 139-146.
  22. Guo, Z. and Wong, K.C. (2005), Skinning with deformable chunks, Computer Graphics Forum (EUROGRAPHICS 05) 24(3), 373-381. https://doi.org/10.1111/j.1467-8659.2005.00862.x
  23. Venkataraman, K., Lodha, S. and Raghavan, R. (2005), A kinematic-variational model for animating skin with wrinkles, Computers & Graphics 29, 756-770. https://doi.org/10.1016/j.cag.2005.08.024
  24. Yang, X.S. and Zhang, J.J. (2006), Automatic muscle generation for character skin deformation, Computer Animation and Virtual Worlds 17, 293-303. https://doi.org/10.1002/cav.133
  25. You, L.H., Yang X.S. and Zhang, J.J. (2008), Dynamic skin deformation with characteristic curves, Computer Animation and Virtual Worlds 19(3-4), 433-444. https://doi.org/10.1002/cav.235
  26. Shen, J., Thalmann, N. M. and Thalmann, D. (1994), Human skin deformation from cross sections, In Proceedings of Computer Graphics International, Melbourne, Australia.
  27. Pyun, H., Shin, H.J. and Shin, S.Y. (2004), On extracting the wire curves from multiple face models for facial animation, Computers & Graphics 28 (5), 757-765. https://doi.org/10.1016/j.cag.2004.06.013
  28. Hyun, D.E., Yoon, S.H., Chang, J.W., Kim, M.S. and Juttler, B. (2005), Sweep-based human deformation, The Visual Computer 21, 542-550. https://doi.org/10.1007/s00371-005-0343-x
  29. Yoon, S.H. and Kim, M.S. (2006), Sweep-based freeform deformations, Computer Graphics Forum 25(3), 487-496. https://doi.org/10.1111/j.1467-8659.2006.00968.x
  30. Jha, K. (2008), Construction of branching surface from 2D contours, International Journal of CAD/CAM 8(1), 21-28.
  31. You, L.H., Rodriguez, J.R. and Zhang, J.J. (2006), Manipulation of Elastically Deformable Surfaces through Maya Plug-in, In Proceedings of International Conference on Geometric Modeling & Imaging, IEEE Computer Society, 15-21.