Optical long baseline interferometry (OLBI) is a powerful tool to study detailed stellar structures. Present optical interferometers attain the milliarcsecond angular resolution allowing this study. In the present contribution I present a physically coherent interferometry oriented model which includes a radiation transfer code. An application of this model to rapid rotators is presented where the effects of gravity darkening and geometrical deformation are included. The high angular resolution signatures due to rapid rotation are shown for several interferometric observables.