AI Working Paper 329 November 1985 Extending 2 - D Smoothed Local Symmetries to 3 - D

3-D Smoothed Local Symmetries (3-D SLS's) are presented as a representation for three-dimensional shapes. 3-D SLS's make explicit the perceptually salient features of 3-D objects and are especially suited to representing man-made objects. The definition of the 3-D SLS is given as a natural extension of the 2-D Smoothed Local Symmetry (2-D SLS). Analytic descriptions of the 3-D SLS are derived for objects composed of planar and spherical patches. Results of an implementation of the 3-D SLS are presented, along with suggestions for further research. AI Laboratory Working Papers are produced for internal circulation, and may contain information that is, for example, too preliminary or too detailed for formal publication. It is not intended that they should be considered papers to which reference can be made in the literature. ( Massachusetts Institute of Technology 1989