Representation and Fast Display of Complex CSG Models

We present a system for fast and accurate display of CSG constructive solid geome try models Such models have as primitives polyhedra and solids whose boundaries can be represented using rational spline surfaces As part of pre processing we compute the B rep boundary representation from the CSG tree and represent the resulting solid using trimmed spline surfaces No assumptions are made on the number of primitives or the degree of the primitives in the CSG tree We also present an accurate e cient and multiresolution representation of the high degree trimming curves Given a trimmed spline model we tes sellate it into polygons as a function of the viewing parameters and render it using visibility computations and coherence between successive frames The choice of a multiresolution rep resentation of the model and the trimming curves is fundamental to the fast performance of the system The system has been used to convert parts of a submarine storage and handling system model represented as more than CSG trees The B rep consists of more than trimmed spline surfaces and is displayed at interactive rates on the Pixel Planes graphics system