Modo Group Mask Support

[WaraCutta]

I'm using a subdivided model and then apply mutiple overlapping displacement maps on it to simulate multiple layers of deformations. However at UV seams, the values do add up and there are cracks in the surface because the displacement value is slightly above zero. To solve this in modo , I create a vertex map with weighting ( let call it vertex map 1 ) for my displacement so that the image is fading toward UV seams , I then go to my material group , in shader tree , add a weight map processing texture ( let's call it weight map texture 1 ), set the weight map ( vertex map 1 ) as the source and then use the weight map texture ( vertex map 1 ) as a group mask. In Modo , it works perfectly , the texture fades at the seams and I get rid of the cracks when I render. But vray doesn't get this into account and keep the cracks in the displacement ... may it be a probleme with weight map processing texture ... weight maps in general ... or group masks ? it would be however really great to have this implemented.

thanks in advance for reading.

[vladimir.nedev]

The problem is probably the "weight map" texture. In V-Ray for MODO, it is supported only for V-Ray Proxy items. But it is best not to use those with displacement. Also exporting to a .vrmesh file will not include vertex maps at the moment.

It's not terribly hard to implement the "weight map" for MODO's geometry, but it needs some optimizations to not include unused mesh vertex maps during export (as that will have an impact on memory usage).

Can you try something else for this particular case. Add the V-Ray Geometry Properties to the mesh, check Enable V-Ray Subdivision and check Keep continuity.

Greetings,
Vladimir Nedev

[WaraCutta]

it works , except for one detail , vray subdivisions do not take into account the modo vertex map used for edge creasing ... is there a workaround ?

[vladimir.nedev]

Check Enable OpenSubdiv instead of Enable V-Ray Subdivision, again in the V-Ray Geometry Properties.
In this case, the vertex/edge creases should work very similar to MODO, if the MODO sub-division type was Catmull-Clark to begin with.
If the mesh is using MODO's own sub-division scheme, the creases might not work similarly enough.

Edit: if it is possible, can you send me the scene, so I can test it when implementing the weight map texture ?

Greetings,
Vladimir Nedev

[WaraCutta]

unfotunately, no , I cannot share it , I apologize for it , but that is why I was trying to accurately describe the issue . I'll be regularly checking the forum anyway. Thank you for your quick reply !

[vladimir.nedev]

Ok, no problem.

Greetings,
Vladimir Nedev

[danklife]

Doing some more tests and it looks like VRay does not support group masks? Is this the case and is there any plan to support it soon? I have attached a project where I used them for graphics on cans.

[vladimir.nedev]

Doing some more tests and it looks like VRay does not support group masks? Is this the case and is there any plan to support it soon? I have attached a project where I used them for graphics on cans. [ATTACH=CONFIG]31768[/ATTACH][ATTACH=CONFIG]31769[/ATTACH]

Group masks are generally supported, in your case there might be a bug or something else that is not supported, like a procedural texture.
The Event Log has warnings on those.
Can you send me this scene, so I can take a look what's wrong ?
E-mail is : vladimir.nedev@chaosgroup.com

Greetings,
Vladimir Nedev

[danklife]

No procedual stuff on the cans. Instances and Library materials though. File incoming VIA WeTransfer just promise not to laugh at the sprawling mess of my working files.

[vladimir.nedev]

No procedual stuff on the cans. Instances and Library materials though. File incoming VIA WeTransfer just promise not to laugh at the sprawling mess of my working files.

Can you send me the image files used for the group masks as well (or even better - all textures) ?
I suspect the problem has something to do with the fact they are psd textures and have "alpha only" enabled.

Greetings,
Vladimir Nedev

[danklife]

Sent. "Consolidate Scene" in Modo appears to not do what it says on the tin.

[vladimir.nedev]

It seems there is a bug when loading the alpha of .psd textures.
I've logged it and will report any progress here.
As a workaround, you can convert your .psd textures to .png and then it should work.
Here is how it looks with .png textures:



Greetings,
Vladimir Nedev

[danklife]

Awesome, many thanks Vlad!