Abstract
Locating an optimal light source is an important task for image synthesis because it influences the spatial perception of the observers. Several methods have been proposed, that search for the optimal location of light sources for 3D surfaces, but none has been done for volumes. This paper presents a new method for finding an optimal location of a single parallel light source for volumetric ray-casting. The method computes the entropy of brightness distribution of representative isosurfaces. The method then utilizes the opacity transfer function to assign a distinct weight to each of the values of isosurface illumination entropy to evaluate the plausible illuminating entropy for the volume. The light with the maximum entropy value allows the observers to realize the volume features with enriched 3D visual cues.
