  This paper covers the time consuming issues intrinsic to physically-based
image rendering algorithms. First, glass materials optical properties were
measured on samples of real glasses and other objects materials inside an hotel
room were characterized by deducing spectral data from multiple trichromatic
images. We then present the rendering model and ray-tracing algorithm
implemented in Virtuelium, an open source software. In order to accelerate the
computation of the interactions between light rays and objects, the ray-tracing
algorithm is parallelized by means of domain decomposition method techniques.
Numerical experiments show that the speedups obtained with classical
parallelization techniques are significantly less significant than those
achieved with parallel domain decomposition methods.
