Fading vray displacement?

[frazer]

I am using a tile map to create a displacement on a plane. This same tile map also effects the colour of the material. So that when the area is white it sticks out alot and when black doesnt stick out at all. This is fine for most the areas the problem is on the lower area. I m wanting the tiling to fade in from flat but do not know how to do this and ideally if possible fade in randomly following the same tile pattern so at the bottom it is just a dark glossy grey as you move up random raised parts appear of lighter colour increasing up to the top where it is completely random.

 

Have enclosed a image to try show what i am doing so far to try help understand better and a earlier test file.

 

Thanks again Frazer.

[Crazy Homeless Guy]

modify you displacement map. i tneeds to be as tall as your displaced obbject, then, inphotoshop, do a gradient fade from black to clear on the lower portion of the displacement map. at the bottom it will be completely black, causing no displace, then as it fades into the disaplcement image, the bumpouts will slowly fade in.

[skogskalle]

or you could try using a "mix" map for displacement, with your tiles-map in one slot, completely black color in the other slot, and finally a black/white gradient in the mix-slot... guess it would produce the same result, and you wouldnt have to re-paint your displacementmap in pshop if you want to change the fading effect. havent tried using a mixmap for displacement myself, but I dont think there should be any problems.