Just finished a bit of housework, so I was away from the PC... thank you all for pondering this question and responding!

Quote - Start with the original texture. Use a brick to subtract white. Then use another brick to add white. This is (x - k) in the first brick.

Then (x - k) + k in the second brick.

If you do not see x, the original image, then something non-linear happened in the middle. If it is completely white, the intermediate value was clamped.

If SM clamps intermediate results (no less than 0, no more than 1) then you are screwed and cannot make the same things as we can in Poser.

Yep, this is what I'm going to generate in SM... and thank you for the recipe. Once again! If SM does clamp values and doesn't deal with hyper/hypo colours, then true: I'll be limited in a lot of things I do. And I mean, a LOT!

Quote - Further: If I sample (not very accurately, I must admit!) the colours that occur in one area of the preview and then sample (again, very approximately) the colours from the same area on the other preview, it appears that something is changing in the red and blue components, too. Which is strange if all you're doing is subtract 128 of green. You'd expect the clamping to show up (if that's what Shader Mixer does) in the green component and leave the red and blue alone. But that's not happening. Every component of the source image is changing.

That's a very good point. Another reason why a bit of documentation as to what the maths bricks actually do with colour math would be helpful. One of the wiser heads on the Daz forum opined: "Your recreation of BB's network looks to be acting as advertised - it's pulled in the extremes of the variation in colour to my (highly unreliable) eyes. However, it's true that the previews often seem to be less than wholly helpful."

Might it be an issue with how the previews are generated? Makes them patently useless, then.

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

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