Abstract: Methods and apparatus for automatically detecting and visually highlighting interference areas of a cross-section through displayed representations of solids. As a cross-sectioning plane (C) sweeps space, interferences between any pairs of solids are visualized, in a highlighted fashion, together with the cross-sections of the solids. The invention also automates the detection, in three dimensions, of regions of interferences. In response to an input, a cross-sectioning plane is initially positioned and a search process is begun. The invention automatically locates a beginning of a three-dimensional interference region along a search direction having a predetermined orientation with the cross-sectioning plane. If an interference is located, a user may analyze the interference interactively through the use of cross-section highlighting. The system positions the cross-sectioning plane automatically at the beginning of the detected interference region so as to facilitate the inspection.

Abstract: A method, and apparatus for practicing the method, processes pixels to display a cross-sectioned image of a solid object. The method includes the steps of, for each pixel that projects onto the solid object, (a) determining, as a function of a depth of a clipping plane at a pixel, a parity of the pixel; and (b) for each pixel determined to have a predetermined type of parity, displaying the pixel with a visual characteristic selected to indicate that the pixel is a pixel that projects onto material that is within an interior of the solid object.