Computer Graphics Laboratory ETH Zurich


Augmenting Physical Avatars Using Projector-based Illumination

A. Bermano, P. Brüschweiler, A. Grundhöfer, D. Iwai, B. Bickel, M. Gross

Proceedings of ACM SIGGRAPH Asia (Hong Kong, November 19 - November 22, 2013), ACM Transactions on Graphics, vol. 32, no. 6, pp. 189:1--189:10
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Animated animatronic figures are a unique way to give physical presence to a character. However, their movement and expressions are often limited due to mechanical constraints. In this paper, we propose a complete process for augmenting physical avatars using projector-based illumination, significantly increasing their expressiveness. Given an input animation, the system decomposes the motion into low-frequency motion that can be physically reproduced by the animatronic head and high-frequency details that are added using projected shading. At the core is a spatio-temporal optimization process that compresses the motion in gradient space, ensuring faithful motion replay while respecting the physical limitations of the system. We also propose a complete multi-camera and projection system, including a novel defocused projection and subsurface scattering compensation scheme. The result of our system is a highly expressive physical avatar that features facial details and motion otherwise unattainable due to physical constraints.

author = {Bermano, Amit and Br\"{u}schweiler, Philipp and Grundh\"{o}fer, Anselm and Iwai, Daisuke and Bickel, Bernd and Gross, Markus},
title = {Augmenting Physical Avatars Using Projector-based Illumination},
journal = {ACM Trans. Graph.},
issue_date = {November 2013},
volume = {32},
number = {6},
month = nov,
year = {2013},
issn = {0730-0301},
pages = {189:1--189:10},
articleno = {189},
numpages = {10},
url = {},
doi = {10.1145/2508363.2508416},
acmid = {2508416},
publisher = {ACM},
address = {New York, NY, USA},
keywords = {animatronics, projector-camera systems},
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