A fast shaded-polygon renderer

ABSTRACT

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.

REFERENCES

• 1: Bresenham, J.E, Algorithm for computer control of a digital plotter. IBM Systems Journal 4. I (1965),25-30.
• 2: James D. Foley , Andries Van Dam, Fundamentals of interactive computer graphics, Addison-Wesley Longman Publishing Co., Inc., Boston, MA, 1982
• 3: Henry Fuchs , Jack Goldfeather , Jeff P. Hultquist , Susan Spach , John D. Austin , Frederick P. Brooks, Jr. , John G. Eyles , John Poulton, Fast spheres, shadows, textures, transparencies, and imgage enhancements in pixel-planes, ACM SIGGRAPH Computer Graphics, v.19 n.3, p.111-120, Jul. 1985
• 4: Gouraud, H., Continuous shading of curved surfaces. IEEE Transactions on Computers C-20. 6 (June, 1971), 623-629.
• 5: William M. Newman , Robert F. Sproull, Principles of interactive computer graphics (2nd ed.), McGraw-Hill, Inc., New York, NY, 1979
• 6: Hiroyuki Sato , Mitsuo Ishii , Keiji Sato , Morio Ikesaka , Hiroaki Ishihata , Masanori Kakimoto , Katsuhiko Hirota , Kouichi Inoue, Fast image generation of construcitve solid geometry using a cellular array processor, ACM SIGGRAPH Computer Graphics, v.19 n.3, p.95-102, Jul. 1985

INDEX TERMS

Classification:
  B. Hardware
  B.2 ARITHMETIC AND LOGIC STRUCTURES
      B.2.1 Design Styles
          Subjects: Pipeline

  I. Computing Methodologies
  I.3 COMPUTER GRAPHICS
      I.3.3 Picture/Image Generation
          Subjects: Display algorithms

  J. Computer Applications

General Terms:
Algorithms, Design