Cost Prediction in Ray Tracing
Although it is generally known that ray tracing is ‘time consuming’, yet rewarding with respect to image quality, there are few attempts to predict the rendering time for a given model in advance. This paper focusses on the development of such a technique.
The cost of ray tracing using adaptive spatial subdivisions has been studied by analysing the probability that a ray intersects an object. Per spatial subdivision cell the surface area relative to the cell size provides a measure for this probability. This cost function is refined by taking into account possible overlap when multiple objects inhabit the same cell. A further refinement is applied by computing the average tree depth of the spatial subdivision and by assuming that each ray will on average traverse the spatial subdivision at this depth. To evaluate and validate our method we applied it to some complex models and compared the results with the actual rendering cost.
KeywordsIntersection Test Leaf Cell Blocking Factor Spatial Subdivision Octree Cell
Unable to display preview. Download preview PDF.
- 1.Ward, G. J.: ‘The radiance lighting simulation and rendering system’, ACM Computer Graphics pp. 459–472. (1994) SIGGRAPH ’94 Proceedings.Google Scholar
- 2.Haines, E. A.: Standard procedural database, v3.1. 3D/Eye. (1992)Google Scholar
- 3.Reinhard, E., Jansen, F. W.: ‘Pyramid clipping’, Ray Tracing News, volume 8, number 2. (1995)Google Scholar
- 6.Whang, K.-Y., Song, J.-W., Chang, J.-W., Kim, J.-Y., Cho, W.-S., Park, C.-M., Song, I.-Y.: ‘Octree-r: An adaptive octree for efficient ray tracing’, IEEE Transactions on Visualization and Computer Graphics 1(4), 343–349.Google Scholar
- 7.Subramanian, K. R., Fussell, D. S.: ‘Automatic termination criteria for ray tracing hierarchies’, Graphics Interface ’91 pp. 93–100. (1991)Google Scholar