Shade trees

ABSTRACT

Shading is an important part of computer imagery, but shaders have been based on fixed models to which all surfaces must conform. As computer imagery becomes more sophisticated, surfaces have more complex shading characteristics and thus require a less rigid shading model. This paper presents a flexible tree-structured shading model that can represent a wide range of shading characteristics. The model provides an easy means for specifying complex shading characteristics. It is also efficient because it can tailor the shading calculations to each type of surface.

REFERENCES

• 1: James F. Blinn , Martin E. Newell, Texture and reflection in computer generated images, Communications of the ACM, v.19 n.10, p.542-547, Oct. 1976 [doi>10.1145/360349.360353]
• 2: James F. Blinn, Models of light reflection for computer synthesized pictures, ACM SIGGRAPH Computer Graphics, v.11 n.2, p.192-198, Summer 1977
• 3: James F. Blinn, Simulation of wrinkled surfaces, ACM SIGGRAPH Computer Graphics, v.12 n.3, p.286-292, August 1978
• 4: James Frederick Blinn, Computer display of curved surfaces., 1978
• 5: James F. Blinn, Light reflection functions for simulation of clouds and dusty surfaces, ACM SIGGRAPH Computer Graphics, v.16 n.3, p.21-29, July 1982
• 6: Edwin Earl Catmull, A subdivision algorithm for computer display of curved surfaces., 1974
• 7: R. L. Cook , K. E. Torrance, A Reflectance Model for Computer Graphics, ACM Transactions on Graphics (TOG), v.1 n.1, p.7-24, Jan. 1982 [doi>10.1145/357290.357293]
• 8: COOK, ROBERT L., LOREN CARPENTER, THOMAS PORTER, WILLIAM REEVES, DAVID SALESIN, AND ALVY RAY SMITH, "Road to Point Reyes," Computer Graphics, vol. 17, no. 3, July 1983. title page picture
• 9: GARDNER, GEOFFREY Y., EDWIN P. BERLIN JR., AND BOB GELMAN, "A Real-Time Computer Image Generation System Using Textured Curved Surfaces," The 1981 Image Generation/Display Conference II, pp. 60-76, June 1981.
• 10: Henri Gouraud, Computer display of curved surfaces, 1971
• 11: HALL, ROY A. AND DONALD P. GREENBERG, "A Testbed for Realistic Image Synthesis," IEEE Computer Graphics and Applications, vol. 3, no. 8, pp. 10-20, November 1983.
• 12: HULST, H. C. VAN DE, Light Scattering by Small Particles, pp. 228-266, Dover, New York, 1957.
• 13: MCCARTNEY, EARL J., Optics of the Atmosphere, pp. 1-49, John Wiley & Sons, New York, 1976.
• 14: MINNAERT, M., The Nature of Light and Color in the Open Air, Dover, New York, 1954.
• 15: 15. NUSSENZVEIG, H. MOYSES, "The Theory of the Rainbow," Scientific American, vol. 236, no. 4, pp. 116-127, April 1977.
• 16: Bui Tuong Phong, Illumination for computer generated pictures, Communications of the ACM, v.18 n.6, p.311-317, June 1975 [doi>10.1145/360825.360839]
• 17: David R. Warn, Lighting controls for synthetic images, ACM SIGGRAPH Computer Graphics, v.17 n.3, p.13-21, July 1983
• 18: Turner Whitted, An improved illumination model for shaded display, Communications of the ACM, v.23 n.6, p.343-349, June 1980 [doi>10.1145/358876.358882]
• 19: T. Whitted , D. M. Weimer, A Software Testbed for the Development of 3D Raster Graphics Systems, ACM Transactions on Graphics (TOG), v.1 n.1, p.43-58, Jan. 1982 [doi>10.1145/357290.357295]

INDEX TERMS

Primary Classification:
  I. Computing Methodologies
  I.3 COMPUTER GRAPHICS
      I.3.7 Three-Dimensional Graphics and Realism

Additional Classification:
  E. Data
  E.1 DATA STRUCTURES
      Subjects: Graphs and networks; Trees

General Terms:
Algorithms, Design

Keywords:
Color, Computer Graphics, Illumination, Lighting, Reflection, Shading, Shadows, Texture