Evaluate noise map. v = a_noise(x,y,z)?

I'd like to evaluate a noise map (or any 3d map) at an arbitrary point in space.

v = a_noise(u,v,w)

Guess it would return an rgb value. With or without other mappings or materials involved. I guess ideally I would do my own mapping. So u,v,w would be 0.0 - 1.0 I presume.

I spent some time poking around, but couldn't find it. But I'm a total noob.

- gruhn