I have created a basic voronoi function that looks like rocks on the shore of a lake. What I want to do is stop the rocks at a certain height. How do I limit the height of the function specifically.
My only thought would be to use a distribution shader set at maximum altitude or slope.
Surface layers can do this also. A surface layer also allows adding displacement directly using the displacement input. This can be a power fractal, redirect shader, or a node tree.
Do I plug the displacement shader into the input of the surface layer?
Go to the displacement tab of the surface layer. Use the box on the right of the input and use assign to link to the last link of the displacement node.
Is the layer which generates the voronoi a surface layer? If so, then use the surface layer's own restriction parameters.
If not, if it is generated using a displacement shader, then connect the output of the displacement shader into the child-layer port of either a surfacelayer or distributionshader and use their restriction parameters.
This should work, otherwise you can post your tgd (or an example) so we can figure it out for you.
Cheers,
Martin