filename     : Bar12.pdf
entry        : article
conference   : Computer Graphics Forum (Proceedings of Eurographics, Cagliari, Italy, May 13-18, 2012)
pages        : 603-610
year         : 2012
month        : May
title        : Manufacturing Layered Attenuators for Multiple Prescribed Shadow Images
subtitle     :
author       : Ilya Baran and Philipp Keller and Derek Bradley and Stelian Coros and Wojciech Jarosz and Derek Nowrouzezahrai and Markus Gross
booktitle    : Proceedings of Eurographics
ISSN/ISBN    : 0167-7055
editor       : P. Cignoni and T. Ertl
publisher    : Blackwell Publishing Ltd.
publ.place   :
volume       : 31
issue        : 2
language     : English
keywords     : 
abstract     : We present a practical and inexpensive method for creating physical objects that cast different color shadow im- ages when illuminated by prescribed lighting configurations. The input to our system is a number of lighting con- figurations and corresponding desired shadow images. Our approach computes attenuation masks, which are then printed on transparent materials and stacked to form a single multi-layer attenuator. When illuminated with the input lighting configurations, this multi-layer attenuator casts the prescribed color shadow images. Alternatively, our method can compute layers so that their permutations produce different prescribed shadow images under fixed lighting. Each multi-layer attenuator is quick and inexpensive to produce, can generate multiple full-color shadows, and can be designed to respond to different types of natural or synthetic lighting setups. We illustrate the effectiveness of our multi-layer attenuators in simulation and in reality, with the sun as a light source.