Spectral and Wave Rendering
Spectral Ray Differentials
Article first published online: 15 JUL 2014
© 2014 The Author(s) Computer Graphics Forum © 2014 The Eurographics Association and Blackwell Publishing Ltd. Published by Blackwell Publishing, 9600 Garsington Road, Oxford OX4 2DQ, UK and 350 Main Street, Malden, MA 02148, USA.
Computer Graphics Forum
Volume 33, Issue 4, pages 113–122, July 2014
How to Cite
Elek, O., Bauszat, P., Ritschel, T., Magnor, M. and Seidel, H.-P. (2014), Spectral Ray Differentials. Computer Graphics Forum, 33: 113–122. doi: 10.1111/cgf.12418
- Issue published online: 15 JUL 2014
- Article first published online: 15 JUL 2014
Light refracted by a dispersive interface leads to beautifully colored patterns that can be rendered faithfully with spectral Monte-Carlo methods. Regrettably, results often suffer from chromatic noise or banding, requiring high sampling rates and large amounts of memory compared to renderers operating in some trichromatic color space. Addressing this issue, we introduce spectral ray differentials, which describe the change of light direction with respect to changes in the spectrum. In analogy with the classic ray and photon differentials, this information can be used for filtering in the spectral domain. Effectiveness of our approach is demonstrated by filtering for offline spectral light and path tracing as well as for an interactive GPU photon mapper based on splatting. Our results show considerably less chromatic noise and spatial aliasing while retaining good visual similarity to reference solutions with negligible overhead in the order of milliseconds.