Near-infrared and mid-infrared broad band interferometric observations of young stellar objects trace the inner part of the warm dusty circumstellar environment (smaller than a few AUs) and can be used to constrain its physical properties, in particular to characterize the size, location and composition of the emitting region. Because the spatial frequency coverage of current instruments remain sparse, modeling, including detailed radiative transfer (RT), is necessary to get a precise estimate of these properties.