Selectively creating vertical rock faces?

Started by yesmine, April 06, 2014, 06:01:40 PM

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yesmine

I've been reading about and experimenting with examples for generating vertical rock faces, strata, and cliffs, but thought I'd ask if anyone already knows a simple way to do something like what's in the attached image. The examples I've seen seem to be more for generating vertical rock faces and plateaus everywhere in a scene, but I'd like to be able to control where it happens since I'm working with a DEM and the vertical rock faces need be where they should. I thought maybe a Distribution Shader could be used to restrict the effect to slopes over 80-85 degrees, slopes essentially vertical already. But I haven't had much luck yet. Could a Painted Shader let me paint where I want the effect to apply, and manage it that way?
Any suggestions would be a big help.
Thanks..

yossam

A simple shape would restrict the area to what you want.  ;)

Dune

If the vertical areas are on a certain height, you could use a distribution shader (or surface shader) with height control. But as soon as levels vary, that will be hard. Painted shader is an idea, or try to paint a mask over the DEM in PS.

yesmine

So far, a simple shape shader or painted shader does give nice control over where the cliffs/outcrops occurs. The painted shader is very useful, and simple, but a bit trickier to control exact dimensions since it's essentially sprayed on. A simple shape shader definitely has it's up side since the rocky spires and faces tend to be fairly vertical at along the outer edges. But the shape shader rectangle can't be flipped up vertically to fit the exact mountainside(or can it?), so it's more problematic to get it to fit the exact area of the cliff face. I'm still testing though, and both shaders will control where the rocky look appears, which is very handy.

Now, anyone know of a terrain clip or other rocky formation that might happen to plug in as rocky spires or as broken rocky faces? I'm testing the strata shader, but it wants to put horizontal plateaus in places, and other desert cliff or desert mesa sample .tgd's seem much more complicated that what I could probably get away with. But so far I'm having some fun experimenting trying to match the sample in the OP...so back to work :)
Thanks for the help.

Dune

You can add several strata shaders (stack them), with different angles, and mask them by PF's (smallest size not too small!), so you can get a mixed variation of strata patches.