Vray DisplacementMod Material ID no continuity!

[joshduncan]

I can't seem to figure out how to apply a displacement map either from an objects multimat or from a direct bitmap too effect only selected polygons of that object.

 

For example i have a 4m x 4m x 4m cube and want a rectangle in the center (1m x 1m) of each face to have a displacement applied while the outside of it remains flat. I can achieve this, but only with gaps between the displaced edges of the 1x1m rectangle and the flat outside polygons...

 

I've tried using all combinations of 3d mapping, 2d mapping, subdiv mapping to no avail. I just can't seem to get "keep continuity" to actually work. \

 

Bellow is what happens with 3D mapping using a bitmap (not 'use object mtl') and toggling between 'keep continuity' on and off.

 

 

\

 

Both have gaps between the displacement map and the flat borders yet for some reason the continuity effects the cubes edges which i am not displacing at all!

 

Applying the displacement map directly in the material (using sub object/multi to determine which polygons to displace via material ID) leaves gaps as well and has a lot less control.

 

I understand the above is rather convoluted and confusing but this is a major issue for me at the moment and i can't seem to get past it!

 

Help would be appreciated!

[Ismael]

Applying the displacement map directly in the material (using sub object/multi to determine which polygons to displace via material ID) leaves gaps as well and has a lot less control.

 

http://forums.cgarchitect.com/31484-vray-displacement-sub-object.html

 

The black outline...

[joshduncan]

So pretty much you can't achieve this without a displacement map which is actually black around the edges so as to not displace on the edges at all.

 

The cube was an example of my problem but i actually have this problem on a more complex shape where all the edges have to be not displaced, going to be a mission trying to uvw map it all to have black edges where i need (not a cube).

 

Even then it's still not going to be 100% welded is it? Wont doing it that way leave it prone to light leaks etc as opposed to using the 'keep continuity' button when it decides to work?

 

Thanks for your advice though, Ismael.

[CliveG]

I dunno if I've missed something Josh, or if you're doing something different but it seems to work for me.

 

 

I've got 3 different displacement jpegs, all with the same noise in the centre and either black, grey or white around the perimeter, affecting each face of a cube, subdivided 8x8 and all seems to happen as it should there.

 

I don't know if this helps but I can't replicate your problem. Perhaps you should grab some screencaps and give us a bit more info?

 

CG