An Algorithm for Generating Anti - Aliased Polygons for 3 - D Applications

An algorithm for generating anti-aliased polygons is described. The algorithm is simple, but powerful, combining color blending, Gouraud shading and Z-buffer hidden surface removal. A test bed has been constructed which consists of a Versabus M68000 computer (the graphics processor) and a custom interface between the M68000 and the frame buffer of a raster display. Written in "C", the package for generating anti-aliased polygons performs all calculations on a line segment basis rather than pixel basis. This requires less memory and can thus be moved to smaller systems. The prototype test results indicate that a higher graphics performance can be achieved on inexpensive systems by this algorithm and implementation. This paper also suggests an alternative to the Red/Green/Blue color representation normally used in color displays by storing intensity and two normalized color components to simplify the calculation involved in anti-aliasing, color blending and shading.