Abstract: Front end processors in a graphics architecture execute parallel scan conversion and shading to process individually assigned primitive objects for providing update pixels. A crossbar along with groups of first-in-first-out registers (FIFOs) accommodates data flow to parallel pixel processors with associated memory capabilities (frame buffer banks) where visibility and blending operations are performed on predetermined sequences of update pixels to provide frame buffer pixels and ultimately display pixels. The pixel processors identify with sequences of pixels in the display in patterns designed to equalize processor loads for pixels located along scan lines of a raster, or distributed over an area. Update pixel data is tagged to identify FIFO groups (pixel processors) individual FIFO selection and output sequence. Temporal priority is accomplished so that primitive data is entered in the frame buffer banks (components) restored to the same order as generated at the central processor (CPU) level.

Abstract: Objects contending for representation in pixels of a graphics display selectively are awarded a fractional area within a pixel on the basis of: coarse calculations in the Z dimension, aggregate demands of the objects and blending techniques free of binary position resolutions. Specifically, the area occupied by a polygon within a pixel is represented using a single number .alpha., which may variously be defined, for example, a value of "0" indicates no area occupied within the pixel, while a value of "255" indicates full pixel coverage. Fine calculations in the Z dimension for binary resolutions are avoided by the blending techniques with attendant antialiasing. A chain of mixer units for storage and blending in pipeline processing compensate the non-associative characteristic of repeated blending.

Abstract: In an area of interest (AOI) display, a detailed image is projected on a screen at the area of interest while a background image is projected on the surrounding area such that the boarder between the two areas varies in an orbital oscillating pattern to accomplish visual blending. A combiner includes a transparent portion to accommodate projection of the background image at the area of interest. The opaque portion carries a mirror to reflect the detailed image filling the area of interest. The combiner is oscillated in an orbital pattern at a resonant frequency, e.g. 210 Hertz by a three phase electromechanical drive unit.

Abstract: A computer-aided design system and a process generates a graphic display of a blend between a plurality of geometric primitive shapes including other blends. An interactive terminal controls a geometric modeler to generate and modify visual graphic displays of primitive geometric shapes at a display screen of the interactive terminal. Logic structures generate both a blend and blends. Each logic structure is implemented with an individual distinct blending algorithm to accomplish a localized superelliptical blend and blends according to user selections including: a plurality of geometric primitive shapes to be blended, a blend operation, and a blend function. A memory, registers and gates in the system store and manage data.

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.