Incorporation of thermal shadows into real-time infrared three- dimensional image generation

In the infrared spectrum, two contributions to shadows exist: one part is reflective shadows resulting from occlusion of instantly reflected infrared rays, and the other part is thermal (IR) shadows occurring through occlusion of irradiance in the past. The realization of thermal shadows requires a thermal balance calculation in four-dimensions (three-dimensional geometry in one-dimensional time), which is computationally expensive, and therefore mostly used for nonreal-time simulations. We present an approximation of thermal shadows resulting from the occlusion of direct rays from IR emitters. Our approach uses programmable graphics cards to achieve real-time frame rates in scenes with dynamic geometry. © 2014 Society of Photo-Optical Instrumentation Engineers (SPIE) [DOI: 10.1117/1.OE.53.5.053113]