“Improving radiosity solutions through the use of analytically determined form-factors” by Baum, Rushmeier and Winget

  • ©Dan Baum, Holly E. Rushmeier, and James M. Winget




    Improving radiosity solutions through the use of analytically determined form-factors



    Current radiosity methods rely on the calculation of geometric factors, known as form-factors, which describe energy exchange between pairs of surfaces in the environment. The most computationally efficient method for form-factor generation is a numerical technique known as the hemi-cube algorithm. Use of the hemi-cube is based on assumptions about the geometry of the surfaces involved. First, this paper examines the types of errors and visual artifacts that result when these assumptions are violated. Second, the paper shows that these errors occur more frequently in progressive refinement radiosity than in the originally proposed full matrix radiosity solution. Next, a new analytical technique for determining form-factors that is immune to the errors of the hemi-cube algorithm is introduced. Finally, a hybrid progressive refinement method that invokes the new technique to correctly compute form-factors when hemi-cube assumptions are violated is presented.


    1. Akeley, Kurt, Tom Jermoluk, “High Performance Polygon Rendering,” Computer G raphics(SIGG RAPH ‘ 88 Proceedings), Vol.22, No.4, August 1988, pp.239-246.
    2. Afro, James, “Backward Ray Tracing,” Developments in Ray Tracing(SIGGRAPH ’86 Course Notes), Vol. 12, August 1986.
    3. Bergman, Larry, Henry Fuchs, Eric Grant, Susan Spach, ~’Irnage Rendering by Adaptive Refinement,” Computer Graphics (SIGGRAPH ’86 Proceedings), Vol.20, No.4, August I986, pp.29-38.
    4. Cohen, Michael F., Donald P. Greenberg, “The Hemi-Cube: A Radiosity Solution for Complex Environments,” Computer Graphics(SIGGRAPH ’85 Proceedings), Vol.19, No.3, July 985, pp.31-40.
    5. Cohen, Michael F., Donald P. Greenberg, David S. Immel, Philip J. Brock, “An Efficient Radiosity Approach for Realistic Image Synthesis,” IEEE Computer Graphics and Applications, Vol.6, No.2, March 1986, pp.26-35.
    6. Cohen, Michael F., Shenchang Eric Chen, John R. Wallace, Donald P. Greenberg, “A Progressive Refinement Approach to Fast Radiosity Image Generation,” Computer Graphics (SIGGRAPH ’88 Proceedings), Vol.22, No.4, August 1988, pp.75-84.
    7. Cohen, Michael F., “A Consumer’s and Developer’s Guide to Radiosity,” A Consumer’s and Developer’s Guide to Image Synthesis(SIGGRAPH “88 Course Notes), 1988.
    8. Crow, Franklin C., “The Aliasing Problem in Computer- Generated Shaded Images,” Communications of the ACM, Vol.20, No. 11, November 1977, pp.799-805.
    9. Domancich, Micheline. “Graphics Research: A Rambling Tour of French Research Labs Finds Them Hard at Work,” Computer Graphics World (July I988) pp. 113-1 I4.
    10. Goral, Cindy M., Kenneth E. Torrance, Donald P. Greenberg, Bennett Battaile, “Modeling the Interaction of Light Between Diffuse Surfaces,” Computer Graphics(SIGGRAPH’84 Proceedings), Vol. 18, No.3, July 1984, pp.213-222.
    11. Hottel, Hoyt C., Adel F. Sarofim, Radiative Transfer, McGraw- Hill, New York, NY, 1967.
    12. Howell, J. R.,A Catalog of Radiation Configuration Factors, McGraw-Hill, New York, 1982.
    13. Nishita, Tomoyuki, Eihachiro Nakamae, “Continuous Tone Representations of Three Dimensional Objects Taking Account of Shadows and Interreflection,” Computer Graphics (SIGGRAPH ’85 Proceedings), Vol.19, No.3, July 1985, pp.23-30.
    14. Samet, Hanan, Robert E. Webber,”Hierarchicat Data Structures and Algorithms for Computer Graphics, Part lit Applications,” IEEE Computer Graphics and Applications, Voi.8, No.4, July 1988, pp.59-75.
    15. Siegel, Robert, John R. Howell, Thermal Radiation Heat Transfer, Hemisphere Publishing Corp., Washington DC, 1981.
    16. Sparrow, E. M.,”A New and Simpler Formulation for Radiative Angle Factors,” Transactions of the ASME, Journal of Heat Transfer, Vol.85, No.2, 1963, pp.81-88.
    17. Walton, George. N., “Algorithms for Calculating Radiation View Factors Between Plane Convex Polygons with Obstructions,” Fundamentals and Applications of Radiation Heat Transfer (24th National Heat Transfer Conference and Exhibition), HTD-Vol.72, August, 1987, pp.45-52.
    18. Zhu, Yining, Qunsheng Peng, Youdong Liang, “PERIS: A Programming Environment for Realistic Image Synthesis,” Computers and Graphics, Vol. 12, No.3/4, 1988, pp.299-308.

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