A numerical approach to the computation of light propagation through turbid media: application to the evaluation of lighted exit signs

A general event-based Monte Carlo method is presented for numerical quantitative and qualitative analyses relevant to the propagation of light through turbid media such as smoke mixtures and fog. The application of interest is the visualization of lighted safety-related signs seen through fire-caused smoke. The scattering profiles for individual particles are obtained using a laser-based instrument. These are used to numerically model realistic complex, inhomogeneous, and time-varying media for which analytic methods are unavailable and/or intractable. The approach results in high-quality visualizations instead of the usual set of extinction coefficients. The computations are parallelizable on a massive scale and are performed rapidly using a Connection Machine with 32768 processing elements. Experimental results to demonstrate the effectiveness and usefulness of the overall approach are presented