**8. Acknowledgements**

The authors would like to thank Cyberware, Headus, The Scripps Research Institute, Washington University, and Stanford University for providing 3D models. The authors are particularly grateful to Igor Guskov for providing them with the normal meshes, and to Andrei Khodakovsky and Peter Schröder for providing the PGC software.

This research was supported by the Agency for Innovation by Science and Technology (IWT) - Flanders (OptiMMa project) and the Fund for Scientific Research – Flanders (postdoctoral mandate Peter Schelkens and project G014610N).
