“A fast shaded-polygon renderer” by Swanson and Thayer

  • ©Roger W. Swanson and Larry J. Thayer




    A fast shaded-polygon renderer



    Image rendering is the performance bottleneck in many computer-graphics systems today because of its computation-intensive nature. Described here is a one-chip VLSI implementation of a shaded-polygon renderer which provides an affordable solution to the bottleneck. The chip takes advantage of a unique extension to Bresenham’s vector drawing algorithm [1] to interpolate four axes (for Red, Green, Blue and Z) across a polygon, in addition to the X and Y values. Its inherent accuracy and ease of high-speed hardware implementation distinguish this new algorithm from interpolation with incrementing fractions (DDA).This chip was designed as part of a workstation primarily for mechanical engineering CAD applications. The pipelining and internal bandwidth possible on the chip allows rendering speeds of over twelve-thousand, 1000-pixel, shaded polygons per second, suitable for interactive manipulation of solids. Described in this paper is the derivation of the new algorithm and its implementation in a pipelined, polygon-rendering chip.


    1. Bresenham, J.E, Algorithm for computer control of a digital plotter. IBM Systems Journal 4. I (1965),25-30.
    2. Foley, James D., Andreis Van Dam. Fundamentals of Interactive Computer Graphics. Addison-Wesley Publishing Company, Reading, Massachusetts, 1982. 560-561,
    3. Fuchs, Henry, Jack Goldfeather, JeffP. Hultquist, Susan Spach, John D. Austin, Fredrick P. Brooks, Jr., John G. Eyles, and John Poulton. Fast spheres, shadows, textures, transparencies, and image enhancements in Pixel-Planes. Computer Graphics 19. 3 (1985), 111 (Proc. SIGGRAPH 85).
    4. Gouraud, H., Continuous shading of curved surfaces. IEEE Transactions on Computers C-20. 6 (June, 1971), 623-629.
    5. Newman, William M., and Robert F. Sproull, Principles of Interactive Computer Graphics. McGraw-Hill Book Company, New York, 1973.41-45.
    6. Sato, Hiroyuki, Mitsuo Ishii, Keiji Sato, Morio Ikesaka, Hiroaki lshihata, Masanori Kakimoto, Katsuhiko Hirota, Kouichi Inoue. Fast image generation of constructive solid geometry using a cellular array processor. Computer Graphics 19. 3 (1985), 99 (Proc. SIGGRAPH 85).

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