Abstract : Reproducing efficiently the appearance of complex materials is a crucial problem in the synthesis of realistic images widely involved in the production of video games and movies. Apart from global light transport, the realism of a synthetic image is in large part due to the adequate modeling of local light transport, i.e. the interactions between light and matter. Modeling these interactions gives rise to a large variety of reflectance models. We therefore propose a classification of these models based on the scales of their abstract geometric details. From this classification, we can study particular reflectance models: a transmitting reflectance model for transparent rough surfaces such a frosted glass. The efficiency of our model allows real-time performances, a study and a model of energy propagation in material composed of dense packed discrete particles, an alternative basis for representing and lighting efficiently measured materials having a low frequency reflectance. These models permit the abstraction of local interactions while keeping the realism of fully simulated local light transport models.