The Community for Technology Leaders
RSS Icon
Subscribe
Issue No.04 - July/August (2010 vol.30)
pp: 42-50
J.P. Lewis , Weta Digital
Ken-ichi Anjyo , OLM Digital
ABSTRACT
This paper introduces a simple direct manipulation algorithm for the popular blendshape facial animation approach. As is the case for body animation, direct manipulation of blendshape models is an inverse problem: when a single vertex is moved, the system must infer the movement of other points. The key to solving the inverse problem is the observation that the blendshape sliders are a semantic parameterization -- the corresponding blendshape targets have clear, interpretable functions. Distance in "slider space'' is easily computed and provides the necessary regularization for the inverse problem: The change in semantic position is minimized subject to interpolating the artist's direct manipulations. We give empirical and mathematical demonstrations that a single direct manipulation edit is often the equivalent of multiple slider edits, but the converse is also true, confirming the principle that both editing modes should be supported.
INDEX TERMS
blendshape, facial animation, direct manipulation, inverse kinematics, computer graphics, graphics and multimedia
CITATION
J.P. Lewis, Ken-ichi Anjyo, "Direct Manipulation Blendshapes", IEEE Computer Graphics and Applications, vol.30, no. 4, pp. 42-50, July/August 2010, doi:10.1109/MCG.2010.41
REFERENCES
1. M. Unuma, K. Anjyo, and R. Takeuchi, "Fourier Principles for Emotion-Based Human Figure Animation," Proc. Siggraph, ACM Press, 1995, pp. 91–96.
2. A. Bruderlin and L. Williams, "Motion Signal Processing," Proc. Siggraph, ACM Press, 1995, pp. 97–104.
3. K. Yamane and Y. Nakamura, "Natural Motion Animation through Constraining and Deconstraining at Will," IEEE Trans. Visualization and Computer Graphics, vol. 9, no. 3, 2003, pp. 352–360.
17 ms
(Ver 2.0)

Marketing Automation Platform Marketing Automation Tool