One pass per subpixel sample) through the hardware rendering pipeline. The resulting image is very high quality, but the per- formance degrades in proportion to the number of subpixel samples used by the filter function. This paper describes algorithms for accelerating antialiasing in 3D graphics through low-cost custom hardware. The rendering architecture employs a multiple-pass algorithm to perform front-to-back hidden surface removal and shading. Coverage mask evaluation is used to composite objects in 3D. The key advantage of this approach is that antialiasing requires no addi- tional memory and decreases rendering performance by only 30-40% for typical images. The system is image partition based and is scalable to satisfy a wide range of performance and cost constraints. An A-buffer implementation does not require several passes of the object data, but does require sorting objects by depth before compositing them. The amount of memory required to store the sorted layers is limited to the number of subpixel samples, but it is significant since the color, opacity and mask data are needed for each layer. The compositing operation uses a blending function which is based on three possible subpixel coverage components and is more computationally intensive than the accumulation buffer blending function. The difficulty of implementing the A-buffer algorithm in hardware is de- scribed by Molnar (12).