Computer Graphics
TU Braunschweig

Spectral Ray Differentials

Spectral Ray Differentials

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.

Author(s):Oskar Elek, Pablo Bauszat, Tobias Ritschel, Marcus Magnor, Hans-Peter Seidel
Published:June 2014
Journal:Computer Graphics Forum (Proc. of Eurographics Symposium on Rendering EGSR) Vol. 33
Presented at:Eurographics Conference on Rendering Techniques (EGSR)
Note:Received the Best Student Paper award at EGSR 2014

  title = {Spectral Ray Differentials},
  author = {Elek, Oskar and Bauszat, Pablo and Ritschel, Tobias and Magnor, Marcus and Seidel, Hans-Peter},
  journal = {Computer Graphics Forum (Proc. of Eurographics Symposium on Rendering {EGSR})},
  volume = {33},
  number = {4},
  note = {Received the Best Student Paper award at {EGSR} 2014},
  pages = {113--122},
  month = {Jun},
  year = {2014}