Piecewise Planar Surface Models from Sampled Data

Abstract

Interactive visualization of three dimensional data requires construction of a geometric model for rendering by a graphics processor. We present an automated method for transforming dense, uniformly sampled data grids to an irregular triangular mesh that represents a piecewise planar approximation to the sampled data. The mesh vertices comprise surface-specific points, which characterize important surface features. We obtain surface-specific points by a novel application of linear and non-linear filters, and thresholding. We define a procedure for constructing a triangulation, derived from a Delaunay triangulation, that conforms to the sampled data. In our example application, modeling a terrain surface over a large area, an 80% reduction in polygons maintains an acceptable fit. This method also extends to the tessellation of images. Applications include scientific visualization and construction of virtual environments.