Rendering destroys uvw unwrapping

[Dynedain]

I have a pretty complex object involving 3 submats, and a bunch of uvw unwrapping.

If I render with vray, the uvw unwrapping gets destroyed in the render, and then after the render in my viewport.

If I collapse the uvw unwrap to the editable poly before rendering, this doesn't happen (as it shouldn't).

[trixian]

Hmmm..this sounds mysteriously like something I had problems with on my last project....my meticulously unwrapped model got "phooked" mapping half way through the project, and i could not figure out why. Would be strange if vray was the cause of this, but at least it'd be one less bug to hunt. Guess Vlado will need a scene file to accurately reproduce this one though, as I doubt it happens every time.

[instinct]

Is this maybe related to the UVW Bug in max 7.5 Upgrade (The Archvis extension is known to cause uvw problems)

Thorsten

[Dynedain]

Is this maybe related to the UVW Bug in max 7.5 Upgrade (The Archvis extension is known to cause uvw problems)

Thorsten

The problems were involving the new "real world mapping" channel, which I'm not using.

[instinct]

Well when i installed 7.5 on a testmachine it corrupted the old UVW Mappings on a random basis. The uvw was switched to "Face" seemingly...randomly in viewports and after rendering. sounds pretty similar to your problem, hence i asked. As i wasnt using the new UVW mapping at all. Only the default 7.0 UVW Mappings

Thorsten

[Dynedain]

Here is the uncollapsed poly + uvw unwrap modifier:


Without changing anything, here is the vray render


And then the viewport after the vray render


If I dont render, I don't lose the mapping. And if I collapse the modifier stack before rendering, I don't lose the mapping.

[vlado]

Have you installed the hot fix patch for 3dsmax 7.5? If not, try installing it and see if it changes anything.

Best regards,
Vlado

[Dynedain]

That hotfix was to fix something caused by having cebas plugins.

I've never had any cebas plugins installed, but I'll try it anyways.

[Dynedain]

nope, the hotfix does nothing

[Morbid Angel]

thats the reason we are using max 7.1 ...

[Dynedain]

This was quite a while ago, but since this thread is being mentioned and accusing Vray of problems that isn't its fault, I'd like to take a second to post the resolution.

Vray was not the problem here. In fact, Max 7.5 (or Max at all) was not the problem. This was purely user error. Somehow, I had duplicated the elements of my subobject. So my chair had 2 cushions, 2 armrests, 2 backs, etc, but only one chair object. This is why it seemed the uvwmapping was getting destroyed. One set of elements had the mapping, the other didn't. And when you have coplanar faces (two faces existing in the exact same place, like using snap to put two boxes flush to each other) any rendering engine will have problems because it wont know which face to use. It doesn't know which is in front, and which is behind.

So, please don't use this thread as an example of a problem with Max or VRay, because it isn't a problem with either, it was a problem with the user.

ID10T error, or "PEBCAC" (Problem Exists Between Computer And Chair) error.

[DaForce]

Its always the simplest things isnt it.

Atleast you got it sorted out.