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In the 4th edition, there's no support for RGB rendering--it's always and only spectral. And admittedly the spectral rendering option in earlier editions wasn'
by mattpharr 3y ago
In the 4th edition, there's no support for RGB rendering--it's always and only spectral.
And admittedly the spectral rendering option in earlier editions wasn't great. We didn't always correctly distinguish between illuminants and reflectances, used a fixed binning of wavelength ranges (vs stochastically sampling wavelengths), and had a fine-but-not-state-of-the-art RGB -> Spectrum conversion algorithm. All of that is much better / state of the art in the 4th edition.
- V1ndaar 3y agoOh, thanks a lot for the clarification! And thanks for the work on the book in general. :) I need to look into the changes then. The spectrum implementation of the 3rd version served as inspiration for an X-ray raytracer I've been working on.
- pixelesque 3y agoI've had a quick look in spectrum.cpp, but can't obviously find it: what uplifting method are you using now? Is it something similar to Wenzel and Jo's one, or Alex Wilkie's Sigmoid variation? Edit: ah: RGBSigmoidPolynomial...
- mensetmanusman 3y agoDoes any open source package like Blender support spectral rendering? Want to render dichroic glass :)
- dantondwa 3y agoFor Cycles, it’s in the works but it will take a while. You can use LuxCoreRenderer with Blender, though!
- ska 3y agoNice work! This was a (small) wart in previous. It's a great text, and remains one of my go-to examples when someone asks for examples of well executed technical book. I was only ever peripherally involved in this area as a but found myself revisiting the origin just because it was put together so cleanly.