James F. Blinn
Abstract
In 1974 Catmull developed a new algorithm for rendering images of bivariate surface patches. This paper describes extensions of this algorithm in the areas of texture simulation and lighting models. The parametrization of a patch defines a coordinate system which is used as a key for mapping patterns onto the surface. The intensity of the pattern at each picture element is computed as a weighted average of regions of the pattern definition function. The shape and size of this weighting function are chosen using digital signal processing theory. The patch rendering algorithm allows accurate computation of the surface normal to the patch at each picture element, permitting the simulation of mirror reflections. The amount of light coming from a given direction is modeled in a similar manner to the texture mapping and then added to the intensity obtained from the texture mapping. Several examples of images synthesized using these new techniques are included.
- 1 Bui-Tuong Phong. Illumination for computer generated images. Comm. ACM 18, 6 (June 1975), 311-317. Google Scholar
Digital Library
- 2 Catmuli, E.A. Computer display of curved surfaces. Proc. Conf. on Comptr. Graphics, Pattern Recognition, and Data Structure, May 1975, pp. ll-17 (IEEE Cat. No. 75CH0981-1C).Google Scholar
- 3 Crow, F.C. The aliasing problem in computer-synthesized shaded images. Tech. Rep. UTEC-CSC-76-015, Dep. Comptr. Sci., U. of Utah, Salt Lake City, Utah, March 1976.Google Scholar
- 4 Forrest, A.R. On Coons and other methods for the representation of curved surfaces. Computer Graphics and Image Processing 1 (1972), 341.Google ScholarCross Ref
- 5 Gouraud, H. Computer display of curved surfaces. Tech. Rep. UTEC-CSC-71-113, Dep. Com ptr. Sci., U. of Utah, Salt Lake City, Utah, June 1971.Google Scholar
- 6 Newell, M.E., Newell, R.G., and Sancha, T.L. A solution to the hidden surface problem. Proc. ACM 1972 Ann. Conf., Boston, pp. 443-450. Google ScholarDigital Library
- 7 Oppenheim, A.V., and Schafer, R.W. Digital Signal Processing. Prentice-Hall, Englewood Cliffs, N.J., 1975, pp. 26-34.Google Scholar
- 8 Sutherland, I.E., Sproull, R.F., and Schumaker, R.A. A characterization of ten hidden-surface algorithms. Computing Surveys 6, 1 (March 1974), 1-55. Google ScholarDigital Library
- 9 Warnock, J.E. A hidden-line algorithm for halftone picture representation. Rep. TR 4-15, Dep. Comptr. Sci., U. of Utah, Salt Lake City, Utah, 1969.Google Scholar
- 10 Watkins, G.S. A real-time visible surface algorithm. Tech. Rep. UTEC-CSC-70-101, Dep. Comptr. Sci., U. of Utah, Salt Lake City, Utah, June 1970.Google Scholar
Index Terms
- Texture and reflection in computer generated images
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