Abstract: A line-filtering antialiasing apparatus for a computer graphics display, with a set of parallel pixel processors functioning independently in a line drawing system and with plotting apparatus assigning individual pixels to the processors so as to track to the line. An optimum number of sixteen processors filter proximity data based on the vertical distance from a pixel center to the line center for shading pixels to gray-scale intensity in an area of influence four pixels wide. Line terminations are extended and shaded at the termination area. Pixel values for individual lines are summed to develop a total display image.
Abstract: Methods and apparatus for rendering a spacial contour texture map onto a generally planar polygon for display on the screen of a video monitor in a computer graphic system includes a memory for storing spacial distance measures between the individual texels of the contour texture map and a boundary on the contour texture map as well as an indentifier flag to define whether the texel is on one side of the boundary or the other. The contour texture map is applied to a modeled polygon by computing the intersection of each direction vector extending from an eyepoint through the center of a selected pixel to the contour texture map in a map space coordinate system. The projected size of a pixel on the contour texture map is also computed. The distance between the intersection point of each direction vector and the boundary of the contour texture map is computed and is projected onto the pixel space, that is, the screen of the display monitor.
Abstract: A system is disclosed for subdividing parametric patches for use in a computer graphics system to develop images. The system utilizes initial data, provided as by an interactive user, to represent control points for an initial patch from which the system rapidly computes control points for subpatches using parallel processors. The disclosed system is recursive so that each level of subdivision leads to greater refinement of an initial patch. In one embodiment, the processors in the system compute multiple control points, the grouping of processors exploiting patch symmetrical properties.
Type:
Grant
Filed:
October 3, 1985
Date of Patent:
February 24, 1987
Assignee:
Evans & Sutherland Computer Corporation
Inventors:
Alan B. Hayes, Russell A. Brown, Thomas W. Jensen, Bruce K. Madsen