Spectral rendering, part 2: Real-time rendering
10 days ago
- #real-time-rendering
- #monte-carlo-integration
- #spectral-rendering
- Spectral rendering involves integrals over illuminant and reflectance spectra to determine pixel colors.
- Monte Carlo integration and importance sampling are key techniques for efficiently evaluating these integrals.
- A density function for wavelength sampling is defined, incorporating illuminant spectra and color matching functions.
- Implementation involves precomputing a lookup table for efficient importance sampling and using stratified sampling to reduce variance.
- Spectral BRDFs are adapted to work with reflectance spectra, allowing for accurate color representation.
- Color noise from spectral rendering is manageable, especially with good importance sampling strategies.
- Handling multiple illuminants requires advanced strategies like wavelength guiding or combining spectra.
- Performance measurements show spectral rendering introduces only a modest overhead compared to RGB rendering.
- Spectral rendering is a mature technology compatible with both path tracers and rasterizers, offering advantages over RGB rendering.
- The final part of the series will explore differences between spectral and RGB rendering results.