Physically Inspired Stretching of Non-rigid Bodies

Comenius University

We propose a physically inspired stretching model for non-rigid bodies with linear skeletons. Given an input model composed of linear skeleton segments, it extract scaling matrices that can be directly used in skinning animation. The stretching model evaluates stretching of the body cause by gravitational force and stretching of the body caused by muscle contraction. Our model is based on small deformation theory, which can be directly applied on cylindrical shapes. Since the input body may differ from a cylindrical shape, it is decomposed into several cylindrical parts and stretching factors are calculated for each part individually. Next, the body is stretched along the skeleton based on the function derived from the sum of skeleton curvature. Finally, a system for the visualization of a particle-based simulation using linear blend skinning is created and enhanced with out stretching model.


Paper [PDF ~1.7MB]
Source code available as part of OpenWorm project on github


Michal Piovarči, Martin Madaras, Roman Ďurikovič Physically Inspired Stretching of Non-rigid Bodies, SCCG '15 Proceedings of the 31st Spring Conference on Computer Graphics

  author = {Piovar\v{c}i, Michal and Madaras, Martin and \v{D}urikovi\v{c}, Roman},
  title = {Physically Inspired Stretching for Skinning Animation of Non-rigid Bodies},
  booktitle = {Proceedings of the 31st Spring Conference on Computer Graphics},
  series = {SCCG '15},
  year = {2015},
  isbn = {978-1-4503-3693-2},
  location = {Smolenice, Slovakia},
  pages = {47--53},
  numpages = {7},
  url = {},
  doi = {10.1145/2788539.2788545},
  acmid = {2788545},
  publisher = {ACM},
  address = {New York, NY, USA},