With Vue, you can take any texture image (suitable ones prefferably like lichen, moss, rock etc), and put them into a mixed material, then drive it with a fractal or noise node, the end result is a blending of the two!

That's how I make landscape materials.
http://www.silverblades-suitcase.com/tutorials/htm/6.html

Sorry I don't do more free materials, I'd love to, but...I need ot make some money to pay for all the Vue, Poser etc stuff I buy, sorry!

As said, my dirt map material is one of the best things you'll ever find, if you figure out why...

look at a typical house or wall or whatever material...
duplicate the objects...and it's damned obvious they are simple clones as the material is exactly the same (and often too clean).

Add my dirt map material and...voila', not so similar any more...also, it does add more "realism" by aging/dirtying things. You can easily add it to any material, and increase/decrease amount, colour etc to suit the object.

Two cubes, same material, but, dirt map added to the one on right...

I've collected textures for many years, 3D world magazine usually has a bunch on every CD :)

"I'd rather be a Fool who believes in Dragons, Than a King who believes in Nothing!" www.silverblades-suitcase.com
Free tutorials, Vue & Bryce materials, Bryce Skies, models, D&D items, stories.
Tutorials on Poser imports to Vue/Bryce, Postwork, Vue rendering/lighting, etc etc!