A general simulation method for three-dimensional surface advancement has been developed and coupled with physical models for etching and deposition. The surface advancement algorithm is based on morphological operations derived from image processing which are performed on a cellular material representation. This method allows arbitrary changes of the actual geometry according to a precalculated etch or deposition rate distribution and can support very complex structures with tunnels or regions of material which are completely disconnected from other regions. Surface loops which result from a growing or etching surface intersecting with itself are inherently avoided. The etch or deposition rate distribution along the exposed surface is obtained from macroscopic point advancement models which consider information about flux distributions and surface reactions of directly and indirectly incident particles.>