AcademySoftwareFoundation / OpenPBR

Specification and reference implementation for the OpenPBR Surface shading model
Apache License 2.0
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question regarding color value range enforcement #149

Open Sam-Izdat opened 6 months ago

Sam-Izdat commented 6 months ago

Hi. Quite excited about the work you're doing.

Reading over the white paper, I noticed that the acceptable range for color values is set to be [0,1]. Does this imply that nonconforming color spaces should be excluded?

For example, ACES 2065-1, CIE LAB/LUV and OKLAB can have negative color values. Now, perceptual color spaces might be a questionable choice here, but it seems conceivable that someone would want to define their materials with AP0 primaries.

meshula commented 4 months ago

The answer from games folks is that spectral rendering in real time engines is done to support creating training data for ML to simulate vehicle cameras have which tend to be be infrared sensitive. Spectral light sources are also in their infancy, but rendering in that case is still for the most part done in a wide gamut space like ACEScg. Still early days.