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
Abstract
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.
