Assign vraydisplacemod to part of an object only?

[stayinwonderland]

I've wondered about this for a while now...

 

I have a wall geometry that I've applied a multi-subobject material to so that I can have bricks on the outside and smooth plaster on the inside. I apply a vraydisplace mod to the object to bring out the bricks but it gets applied to the whole thing, exterior AND interior.

 

Ah, you may say, just apply the vraydisplace material instead... but then I get broken edges in my geometry. I can control that with the mod by ticking the continuity box.

 

suggestions? I know VRDmod has a texture channel option but can't see how that would help?

[Ismael]

I think you select the 'brick' polygons of the wall and view the "Polygon: Material IDs rollout"

See which ID (corresponding to the multisub material assigment) Create a UV map for it and assign

the ID number. Apply the Vray Displace mod and point it to the same ID channel?

[stayinwonderland]

I don't think that's gonna work. There's a difference between UV channels and material ids. Plus my brick geometry is ID #1 and all other geometry is ID#2. The UVW channel is #1 and so is the displacement channel, so they are already pointing in the right place.

[Ismael]

http://forums.cgsociety.org/showthread.php?t=398065

[salvador]

Use Displace slot in the material but make sure your displaced faces and thier adjacent faces are on the same smoothing group. That's it. No broken edges.

[stayinwonderland]

Ah... interesting! So I did that and it works. Only thing is, it sort of shouldn't work because if you have a brick wall that turns a corner, you want that corner to be sharp - if you then have both faces on the same smoothing group it tries to blend the two corners. Looks bad in the viewport but renders ok... ? Thoughts?

[salvador]

Ok.

 

One, you can cut two adjacent faces very close to the corner. This way the smoothing is minimized.

 

Two, (not quite sure yet) set the smoothing angle to 90 degrees to force max not to smooth faces.