This paper presents techniques in image simulation and computer graphics intended to generate models to be used for a better understanding of SAR images; only geometric aspects are considered. A fractal relief model is used as a basis for creating simulated SAR pictures. The technique employed is bidimensional Fourier filtering. The relief aspect is controlled by the filter shape. A shading model and algorithm is implemented for the simulation of the coherent lighting in SAR. The model is based on the physics of coherent radiation scattering and propagation. The parameters of the surface are controlled to modify the speckle statistics. The 3D model is presented in a computer graphics station. Due to the high dimension of the scene, heuristic methods are developed for fast ray tracing. Different incident radiation positions and scene projections are available allowing interactive visualization of the synthetic image.