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.

Abstract: A graphics buffer (22) for storing information describing pixels that represent an image. The graphics buffer includes Surface Buffer Modules (32) that include a first memory (46) for storing pixel surface information, such as color, for a plurality of pixels. The Surface Buffer Modules, each further include a first processor (44) coupled to the first memory for modifying pixel information read therefrom and for storing said modified pixel information back into the first memory. The graphics buffer may also include at least one Control Buffer Module (34) that includes a second memory (46') for storing other pixel information, such as pixel flags, and a second processor (44') for modifying the other pixel information. A pixel bus (38) is coupled in common between the Surface Buffer Module and the at least one Control Buffer Module for conveying pixel-related information, including pixel data, pixel addresses, and the results of pixel tests, therebetween.