Surface Reconstruction of Etched Contours

Previously, a computationally efficient and geometrically accurate etching simulation was developed to compute contours of constant depth at different time steps [1]. Experimental verification of this early work has been established [2]. However, contours are not amenable to the analysis and design of microsystems, since it is often necessary to determine object interaction and mechanics in which surface or solid representations of shape are required. Hence, the problem of surface reconstruction is of particular interest. It has been noted that surface reconstruction is an interpolation problem, explaining the predominance of triangulation techniques in many surface reconstruction algorithms [3], [4]. One very effective code, by Boissonnat and others, partitions the contours in a single cross section into Delaunay triangles, then connects the triangles between adjacent cross sections to form Delaunay tetrahedra that can be used for finite element analysis. The surface representation is easily extracted from the bounding tetrahedra. An implementation of Boissonnat’s algorithm to the problem of surface reconstruction of etched contours is discussed. Further, a simple algorithm is presented to remove the bounding triangulations created by Boissonnat’s code (i.e., the surfaces are closed). An application written in TCL and VTK, a freely available highly portable graphical toolkit, to interactively view the resulting surfaces of triangles is discussed.