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Show CHAPTER 8 CONCLUSIONS AND AREAS FOR FUTURE WORK While ray tracing proved to be a computationally intensive approach, it provided a simple framework to calculate terms necessary for the extended radiosity methods. Efforts were made to analyze and optimize the ray tracing techniques to improve ray tracing speed in this context. The ray tracing approach included accurate treatment of Snell's law and the Fresnel reflection law. The slow speed of the form factor calculations was a major limitation of this method. Z-buffer techniques for the directly visible surfaces would almost certainly speed up the whole process. Another approach for form factor calculation might use concepts from path tracing [23,22]. This would be highly advantageous in the cases where the ray trees become wide during form factor sample distribution. The adaptive hierarchical sampling discussed as part of the path tracing variance reduction might also provide considerable savings. Utilization of constraints on the form factors might speed up the calculations. In particular, if the constraints on_ the form factors related to the triangle areas can be used (Equation 4.5 ), the form factor calculation time might be cut by almost half. The number of primary sample rays distributed could be calculated based on the optical characteristics of a surface element. Emitters might have the most samples, |
