Abstract: A Fast Fourier-Transform based shape description method for 3D CAI)models was presented. First,based on uniform representation of geometric facet and according to the facet adjacency relation in the CAI)model, a facet sequcnce was achieved with the hSP( Traveling Salesman Problem) algorithm for complete graphs, and the consistency of the facet sequence was ensured by adopting a reference CAl)model. Then, according to the facet sequence, the geometric information was transformed into five 1D discrete signals. After sampling and amplification, the discrete signals were transformed into frequency domain with FH h and the description of the C八I)model was composed of the magnitudes in frequency domain. If ignoring the deviation caused by facet sequence, describing geometric shapes of CAD models with the method presented in this paper is similar to describing discrete signals with FI门.Experiments were elaborated for physical interpretability too.

Key words: Shape description, Geometric modeling, Fast fourier transform, hravcling sales man problem, Signal processmg