Splitting the reflection phenomenon in a specular and a dioeuse one, current acoustic quality prediction methods can't deal with real materials. In this paper, we describe the implementation of a particle tracing method that can deal with a general model of reflection, the bidirectional reflectance distribution function. Furthermore, being based on the Monte-Carlo methods, this method is not sensitive to combinatorial explosion. The flexibility of the particle tracing method make it a good test bed for comparisons and evaluations of source or reflection models.