Author Topic: How do I measure sRGB values in photoshop? (From Allegorithmic PBR Guides)  (Read 8151 times)

Still, it doesn't make much sense when it works for one color, and doesn't for another. Unless there's some physically-based explanation behind it.

Especially when you think of the colors not in terms of RGB, and some channels being 0, but in terms of hue. Set color to RGB(0,88,0), switch to HSV and move the Hue slider. Repeat for (0,0,255).

I'm using Albedo mode, and the strict 50 sRGB threshold, like I said in the previous post.

It's just an approximation looking at the luminance range of the color value. At the 88 sRGB value then adjusting hue is resulting in some values being a bit dark which is what the validation is looking for. It's converting the color to greyscale to look at luminance range to cap it a rounded range. This is the goal of the validation for PBR. It's looking at overall luminance to equate to the diffuse reflected color for PBR ranges. The 50 sRGB setting is very strict. I'll keep taking a look to see if there is any issues that can be resolved in the node. Thanks for the feedback : )

Cheers,
Wes

Integrations Product Manager / Training
wes.mcdermott@allegorithmic.com
Twitter: The3DNinja

It's converting the color to greyscale

This gave me a clue. Here's a test:

Validation node set to Albedo/50 sRGB
Uniform Color node plugged into Grayscale Conversion node with default settings.

RGB(0,88,0) converts to greyscale (30,30,30), Validation=YES
RGB(0,0,255) converts to greyscale (85,85,85), Validation=NO

This makes no sense. Anyway, thanks for your patience :)

Edit: attached an image, taken just after clicking Compute Nodes Thumbnails to be sure.
Last Edit: June 07, 2016, 08:22:55 pm