How would I create a nice rock shader.

Here's some inspiration for ya: http://forums.odforce.net/index.php?/topic/9532-rock-hard/page__hl__rocks__fromsearch__1 [forums.odforce.net] Not sure all the specifics he did, but procedural noise patterns tend to go well with rocks

Thanks, I created two for loops with a VOP SOP, that multiply 6 iterations and add together to give really realistic rock, now all i have to do is shade it!
This is my first real project in Houdini, apart from tests, so should be good.

Are there examples I can have a look at anywhere?

Not really that I know of. This is the closest thing I could find:
http://www.orbolt.com/asset/SideFX::rockyground [orbolt.com] Macha might be able to provide some more clues to his fancy rocks if you ask him nicely.

I've got the geometry look I want, just need to create a shader, I haven't been able to find many resources for this.

Delight0092
I've got the geometry look I want, just need to create a shader, I haven't been able to find many resources for this.

You might also try http://forums.odforce.net/index.php?/topic/10798-procedural-stonesrocks/ [forums.odforce.net]

There's a .hipnc file along with a texture map which can be used for the rocks.

Do you have reference for what you would like to achieve? Granite [en.wikipedia.org] is a common rock look, but technically obsidian [en.wikipedia.org] is rock as well :shock:, so knowing what you would like to achieve makes a difference in the suggestions you will get.

If you are trying for sand stone or something similar, the clay shader from the material palette may be a good starting point, if not for color patterns then at least for the shading model.

Also, the noise patterns you used in the VOP SOP to create the shape could probably be used to directly drive the mixing of colors for the points. This should make the overall “macro” colors naturally flow with the shape. Same thing goes for sharing displacement noise and fine detail “micro” color noise.

Hey.

I've recently needed procedural rocks and ended up with something like this. The shader itself is pretty simple. Just a bunch of noises. However I'm using an attribute from the geometry called peak (just my name for it), which takes the curvature of the geometry filters out only the peak sharp areas and get's used in a shader to give some color variation to the sharp edges.

I wasn't really going for some specific type of rock, but rather chose the palette and patterns based on what fitted my scene visually.

I'm attaching a file with the vop which calculates this parameter and the shader itself.

The stone geometry was generated using very similar noise patterns as the ones used in the thread mentioned by Mark ( http://forums.odforce.net/index.php?/topic/10798-procedural-stonesrocks/ [forums.odforce.net] )

That's near perfect, with a bit of tweaking!
Granite would suffice, sorry for not specifying anything.