Andrzej Łukaszewski
ABSTRACT
We present independent method to reduce the number of shadow ray tests. It can be used with standard acceleration ray tracing algorithms. Our method is conservative and produces the same results. We test just one shadow ray in modified scene insted of group of rays in original scene. If our ray is not obstructed in modified scene we know that all the rays in this group are not obstructed. The results give rise to many applications when there are many shadow rays e. g., in bidierectional path tracing or stochastically sampling area light sources. The formal proof of the method uses formalism of Minkowski operators and they can also be used in implementation details.
- R. Farouki. Exact Offset Procedures for Simple Solids. Computer Aided Geometric Design, 2(4):257-279, 1985. Google Scholar
Digital Library
- Arno Formella and Christian Gill. Ray Tracing: A Quantitative Analysis and a New Practical Algorithm. The Visual Computer, 11(9):465-476, December 1995.Google ScholarCross Ref
- Andrew Glassner (editor). An Introduction to Ray Tracing. Academic Press, 1989. Google ScholarDigital Library
- E. A. Haines and D. P. Greenberg. The Light Buffer: a Shadow Testing Accelerator. IEEE Computer Graphics and Applications, 6(9):6-16, 1986.Google ScholarDigital Library
- Eric A. Haines. A Proposal for Standard Graphics Environments. IEEE Computer Graphics and Applications, 7(11):3-5, November 1987.Google ScholarDigital Library
- J.-C. Latombe. Robot Motion Planning. Kluwer Academic Publishers, 1991. Google ScholarDigital Library
- A. Łukaszewski. Finding Ray-offset Intersection for Rational Bézier Surfaces. Technical Report 97/04, Institute of Computer Science, University of Wrocław, Poland, May 1997.Google Scholar
- A. Łukaszewski and A. Formella. Fast Penumbra Calculation in Ray Tracing. Sixth International Conference in Central Europe on Computer Graphics and Visualization (Winter School on Computer Graphics), February 1998. Held in University of West Bohemia, Plzen, Czech Republic, 09-13 February 1998.Google Scholar
- J.R. Rossignac and A.A.G. Requicha. Offseting Operations in Solid Modelling. Computer Aided Geometric Design, 3:129-148, 1986. Google ScholarDigital Library
- Eric Veach and Leonidas Guibas. Bidirectional Estimators for Light Transport. In Fifth Eurographics Workshop on Rendering, pages 147-162, Darmstadt, Germany, June 1994.Google Scholar
Index Terms
- Exploiting coherence of shadow rays
Recommendations
Accelerating shadow rays using volumetric occluders and modified kd-tree traversal
HPG '09: Proceedings of the Conference on High Performance Graphics 2009Monte Carlo ray tracing remains a simple and elegant method for generating robust shadows. This approach, however, is often hampered by the time needed to evaluate the numerous shadow ray queries required to generate a high-quality image. We propose the ...
The ray engine
HWWS '02: Proceedings of the ACM SIGGRAPH/EUROGRAPHICS conference on Graphics hardwareAssisted by recent advances in programmable graphics hardware, fast rasterization-based techniques have made significant progress in photorealistic rendering, but still only render a subset of the effects possible with ray tracing. We are closing this ...
Complex Luminaires: Illumination and Appearance Rendering
Simulating a complex luminaire such as a chandelier is expensive and slow, even using state-of-the-art algorithms. A more practical alternative is to use precomputation to accelerate rendering. Prior approaches cached information on an aperture surface ...
Comments