Hi,

because it is so common to not have a roughness map handy in many a texture set, I've just been thinking along the lines of some simple node formula to

basically do what is done in this video: https://www.youtube.com/watch?v=plEgIp1LW2w .

In rough terms, the principle is one node to switch the diffuse map to greyscale, one node to invert that and then another node to play with the contrast of the resulting inverted greyscale map. The result is then a roughness map.

Now I have Ken's "Go Physical" script as a time-saver and it is a great help BUT, it is no solution for the issue of not having a proper roughness map. It's simple "maths function" node method is possibly just a touch too simple to really satisfy me.

So what I have in mind is:

Diffuse > "RGB to BW Node" > "invert" > "contrast node" = "extremely satisfying roughness-map replacement"

You will need to convert the grayscale gamma to 1 before processing through the math nodes.

The best thing to do for roughness is to either not use a map and set it up as variable roughness, or use a map with variable roughness .

Here are some video demonstrating why you would want to do this. None of the included base nodes in Cycles or Superfly know how to do this by default.

Here is how it is done without a map. https://youtu.be/PwhACBSOsyU?si=7A-GgsDkK0USaPHR And this will work for a lot of things. Most actually.

And here is how to do it with the roughness map no one supplies because you don't really need it. https://youtu.be/DrMdUYk-eLA?si=5HXTppCXLDC1Xg69

There are a few ways of getting around the fact that Superfly still doesn't have the required RGB curve node to do this easily.

None of which are simple and strait forward...............

Thank you ever so much.

And in many ways it is what I was looking for.

You know, when I look at potential of Superfly/ Blender's Cycles, I do find it weird that there are so few developers and vendors. I see products for Daz Iray and utterly wonderful packages like Marshian's Tenebroso Lighting and it is strange that there are so few making this for Cycles/Superfly. Likewise, material combinations and alchemy such as what Daz's Dimension Theory did with Tiler Shader (grass shader and more) and RuntimeDna's team did with Terradome2, is almost asking for someone to start cooking with the Cycles/Superfly node based material room.