controlling color fractal distribution by surface displacement roughness?

[TheBadger]

Hello,

I am curious if anyone knows a way to limit where a fractal for color is distributed to areas of a surface based on texture/roughness?

So,
Consider the following image as an example:
[attachimg=1]

Now imagine that the terrain and statues are all one form created in Terragen via a vector displacement...
1) If you wanted to use power fractals as the means to "color" the forms. Is there a way that you can tell Terragen to limit some of the colors to what is the cliffs, and some colors to what are the statues, based on the roughness of the parts?.. That is, some colors assigned to where the terrain is rugged (the cliffs) and some colors where the terrain is smooth (carved smooth statues)? Other than a painted shader, which I find to cumbersome in its present form.

2) Likewise, if I wanted to add noise displacement to the terrain surface (like with a fake stone, or rock face). Can I also limit where that noise happens?.. So I could make the un-carved rocks rugged and natural, and keep the carved rock smooth.

Thank you.

[Tangled-Universe]

I can't quickly think of a way to do this procedurally, wonder if it is even possible.

I'd say:

Make your base terrain without many details.
Make your vector displacement for the shapes you're looking for.
Put the two together and render it out.
Open the render in photoshop and paint over the part which you want to mask.
Use that mask in camera projection mode (image map shader) to mask out areas for displacement and colour.

What do you think?

Martin

[TheBadger]

Probably something like this will work for a still image... I don't mind doing heavy lifting in PS for stills, that seams natural and normal to me.

But as usual I left out important information in my OP (I'm sorry about that)... I want to do an animation (hovering camera or something) The image that I posted is just an example, but its a good example to illustrate the problem Im trying to face.
Ideally the terrain should be one form, in this case created by a vector. In order to keep things clean and simple through the entire process. And so all of the parts line up perfectly.

But I think your words

Put the two together and render it out.

are a way forward. Maybe I can sculpt the statues as a separate layer in Mud, on top of the cliffs. THen save out a vector for each. One for the cliffs first then one for the statues.
Then theoretically I would create the vector terrain first, and then add directly on top of the first vector, the statues vector. Any idea at all if this would work? I just don't know.

Again, Ideally, one vector and away to do the OP idea would be best. Maybe Any more Ideas I can try Martin? I would like to have options in case I get stuck or something does not work all the way through.

Anything at all that sounds reasonable, and is something I can do at my user level... In cases like this I always imagine blue nodes are the answer, But since I cant use those, I just torture my self with the idea..." So and so, could do it with blues! But not me ". 

[Tangled-Universe]

If you want to animate it then you apply the same principles I suggested.

Then you would need to render a top down view of the situation and paint a mask which you can also camera project top down onto the scene.
This way, with a separate projection camera, you avoid the dependance of your render camera.

[Dune]

I think doing the statues separately will work fine. Then make the rocks either procedurally or by MUD and blend the two. You can probably find a way to use the vector mask (with some color adjustments) to separate the colors of the statues from the rest. Just try with a simple setup: a blurb and another blurb.

[TheBadger]

I will try all of your suggestions! Thanks guys.