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5 votes
Accepted

Generating and Combining Spectral Colors

Your way of calculating XYZ functions is probably the most efficient way to go about calculating accurate colors from a spectrum. It is standard practice afaik, for examples the books Physically Based ...
Tare's user avatar
  • 1,566
3 votes
Accepted

Does CIE XYZ preserve spectral accuracy when used for progressive rendering?

The choice of various tristimulus color spaces or spectral rendering matters when you're doing multiplicative color operations, like multiplying a light source color by a material reflectance. For ...
Nathan Reed's user avatar
2 votes

Does CIE XYZ preserve spectral accuracy when used for progressive rendering?

How accurate it is to estimate rendering equation using wavelengths This is probably as accurate as it gets if you are using with the full form of Fresnel equation. then convert result to CIE XYZ ...
Kaan E.'s user avatar
  • 461
2 votes
Accepted

Computing sRGB color from SPDs

Getting sRGB values outside [0, 1] is expected and normal when using spectral rendering. The sRGB gamut only covers a triangle in the middle of the CIE chromaticity space: (diagram from Wikipedia) ...
Nathan Reed's user avatar
1 vote

Does a constant reflection over the light spectrum lead to grayscale value?

I know this is an old question. I did write a spectrum->rgb converter, however all of its relevant parts for this question come from pbr-book source code. Specifically though, the answer is no. ...
Kaan E.'s user avatar
  • 461
1 vote

How is Iridescence handled in a Path Tracer?

Iridesence can be seen in several variations: diffraction as seen in CDs and DVDs (see Stam's SIGGRAPH 1999 paper on this), phase shifting and modulation in multi-layered surfaces as you see in ...
beyond's user avatar
  • 315
1 vote
Accepted

Is spectral response curve and spectral power distribution the same thing?

The book distinguishes a spectral power distribution from a spectral response curve because they are not the same, they are adjoint. The thing about adjoints that makes them a little tricky to wrap ...
Pseudonym's user avatar
  • 781
1 vote

How to determine RGB values given a display spectral response curve?

First off let me say that the first line in 5.2.2 is wrong or misleading when it says "spectral response curves, one for each of red, green, and blue, as emitted by the display". A "...
Timothy Maguire's user avatar
1 vote

How to calculate spatial frequency of an image just in one direction?

You can take a 1D Fourier transform of a row of pixels from the image; it will give you the horizontal frequencies present in that row. You could sample one row out of the image, or else average all ...
Nathan Reed's user avatar

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