VRay 3D Displacement Mapping Problem???

[DIEDBLUE]

I need help!

I am trying to use the VRay displacement modifier on the side of a sphere. I am not wanting to displace the whole sphere but just a group of polygons on the side using a displacement map I created using photoshop. I have tried and failed! The displacement map is a logo and I am trying to imprint this on the side of the sphere but to no avail! I tried doing the same using 2d mapping on a plane and that works no problem at all. Should I be selecting the polygons that I want and setting there material ID. Then should I be creating a multisub material and applying the displacement map to the diffuse channel?

Any help would be appreciated as I am sure this is farily simple!

[DIEDBLUE]

OK so having read through the forums I can see that one possible solution is to use a blend map in order to achieve a displaced region on an object! Can anyone verify that this is indeed the way to go?

One more thing, Is there a way to physically deform the mesh using the displacement map so that the deformed geometry remains a part of the model instead of it being displaced just for the render?

Thanks.

[mike_kennedy]

VRAY displaces at render time to conserve memory. By having the displacement in the scene you would defeat the purpose. Add enough detail to you mesh to make a Displacement modifier look good and you wil see what I mean, plus that is your alternative answer....
Cheers
Mike Kennedy

[DIEDBLUE]

Thanks for the reply,

I have tried using the displacement modifier to displace a group of poly's on the side of a sphere and I think where I've gone wrong is that I was using the 3d mapping part of the displacement modifier when I should have been using the 2d mapping?! When I used the 2d mapping to map a plane I just copied the displacement map from the material slot to the tex map slot in the displacement modifier and rendered and the displacement worked just fine! To do the same except this time on the side of a shere (where it is just a selection of poly's and not all the poly's) do I just do the same thing? ie - select the poly's using polyselect modifier and then apply the displacement modifier to the selected poly's? or do I not even need teh polyselect modifier???

Any help appreciated

Thanks

[vlado]

VRayDisplacementMod does not take face selection in account. The whole mesh is displaced always. If you don't want that, build a displacement map that is black in the regions you do not want displaced.

Best regards,
Vlado