This article describes a method for modeling the propagation of cracks on any 3D surface. This method allows almost any type of cracks on any type of triangulated 3D object. Our model´s main advantage is that it proposes a semi-physical solution, making it both user controllable and easily extensible. We first introduce the general development of cracks. We then present our original model of spectrum stress, followed by a description of the mutual interaction between cracks and stresses. Then, we describe special rendering techniques including the multi-thickness anti-aliasing linked-segment method and the crack mirror special effect. The final section presents intermediate graphical results that review the entire model as well as a set of different crack patterns using various types of material such as concrete, ceramic, mud, and glaze.