Abstract: This paper presented a metamorphosis method based on triangular decomposition for
product shape design. Firstly, two given triangular mesh models were projected on to the surface of a
unit sphere. Secondly, the edge characteristics were calculated. Then the topological model of new
models was got based on the two kinds of triangular decomposition rulers proposed in this paper. So,
the spatial relationships of vertexes and shape features between the middle model and two given
models could be built. Lastly, the new models were made with linear interpolation. Testes indicated
that the proposed approach needed no topological merging and artificial interference and could
preserve the visual features of the given models effectively. It was shown that these characters were
suitable for industrial designers who had no special knowledge about the metamorphosis technologies
to create new shapes for product form design.

Key words: 3D metamorphosis, triangular decomposition rulers, triangular mesh model, product shape
design