Building Helper Bone Rigs from Examples

Proceedings of 19th ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games (I3D 2015), pp.77-84, 2015.

Authors: Tomohiko Mukai

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Abstract: Helper bone system has been widely used in real-time applications to synthesize high-quality skin deformation with linear blend skinning. Even though this technique provides a flexible yet efficient synthesis for a variety of expressive skin deformations, rigging with helper bones is still a labor-intensive process. In this study, we propose a novel method for building helper bone rigs from examples. We used multiple pairs of skeleton pose and desired skin shapes for our system. First, the system estimates the optimal skinning weights and helper bone transformations to reconstruct each example shape. Next, we construct a regression model which maps a primary skeleton pose to the helper bone transformations. The regression model enables a procedural control over the helper bones according to the primary skeleton. This is done at a lower computational cost and memory footprint. In addition, artists can edit the regression coefficient of the helper bone controller to modify deformation behavior. We demonstrate our system’s potential by synthesizing stylized skin deformations in real-time.

Acknowledgements: This study was supported in part by Research and Study Project of Tokai University Educational System Research Organization.

¬©ACM 2015. This is the author’s version of the work. It is posted here for your personal use. Not for redistribution. The definitive Version of Record was published in ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games ’15, http://dx.doi.org/10.1145/2699276.2699278