Mid-surface of a part is currently used as an idealization of 3D shape for purposes of
analysis/simulation of injection molding and other near net shape processes. The mid-surface has
also been proposed as an intermediate representation for feature extraction, and feature
suppression for analysis.
This paper describes a completely automatic procedure to determine the mid-surface of an object
using 2-D Medial Axis Transform (MAT) of each of its faces. Earlier efforts to generate the midsurface either rely on user intervention and expensive ray tracing procedure to identify pairs of
faces that define mid-surface patches or work on a very restricted domain. In the proposed
approach, the 2-D MAT of each face is used to define mid-curves for each face. These mid-curves
are used to obtain the topology of the mid-surface. Pairs of faces corresponding to each midsurface patch are identified using the mid-curves. The mid-curves also form the boundary of the
mid-surface patch in some special cases. Results of implementation on typical objects are presented
and scope for further work has been identified