Quote from: dwilson on February 21, 2009, 12:04:01 AM
I have run into an issue on fixing the rock. Before, i had used a powerfractal for the rock/grass mask because i didn't want the displacement from the rock layer to be where there is grass and vice versa. I agree that it would be better to use the slope controls in the surface layer but I can't use one surface layer as the blending shader for both the rock and the grass. If I invert the blend shader in the surface layer for the rock, the coverage is the same as if it is not inverted. Is there a way to use a mask of what a surface layer doesn't cover without creating a duplicate surface layer with opposite settings which might not be exactly the same? It would be simple if i didn't care about the displacement from the rock layer being on the grass, but i don't want that.
Sorry if that is confusing. Devin
It sounds pretty confusing, yes

However, I think I understand what you want and you can try the following:
Use a powerfractal with a negative offset for patchy rockstructures on the mountain.
Create a surface-layer and set correct heigth/slope-restrictions for where you want your grasses to appear. Use this surface-layer as densityshader for your grass.
Blend the surface-layer with the powerfractal of the rockstructures, and invert it.
You probably already tried it, but... When you connect the output of the powerfractal to a "multiply colour" function-node and connect a "constant colour" to the other input of the mulitply color, you can more or less control how "tight" the mask is. In your case you should increase the constant colour value >1, which will "blow up" the fractal a little bit (depending on the setting of course).
Of course you should connect the output of the multiplier to the blendshader port of your surfacelayer/densityshader. When you invert this blendshader, as said, the blown up fractal will then actually decrease the coverage of the grass on the rocks even more.
Hope that's a bit clear and not confusing

Martin