UV Seam Error - Any Ideas?

RashedAlmetrami

Hey guys,

Had a unwrapped re-top sent to me from an outsourced artist who's done a poor job of hiding UV seams. 

The model has one quite obvious UV seam running down the back; any idea why this shows up? The tangent space is synced, the Bake model and final model all have one single smoothing group and the texture is baked at 8k.



Any help is much appreciated!

musashidan

I would say simply return to the artist in question and request the asset with the problem resolved before payment. And while you're at it you might also request a less lazy and sloppy job on the retop/unwrap.

RashedAlmetrami

@musashidan I'd like to clarify why the issue is happening before we contact the client again. The client supplied the Retop and Unwrap and I have baked/textured the model

Sage

This is probably not your issue but check that the normal map in the color space setting in maya is set to raw and not some color profile like srgb. I think it defaults to that.

NoRank

Check if this issue persists in any other 3d app. I had this problem with substance painter as well and in marmoset and unreal the seam was invisible.

musashidan

What did you use to bake/texture? 

RashedAlmetrami

Thanks for the help guys!

@Sage @NoRank I've tested it in Marmoset, UE4 and Iray and they all have the seam.

@musashidan I've tried baking the textures in both Xnormal and substance painter and it's present in both results. 

Averaged cage in Xnormal and no cage in Substance Painter.

RashedAlmetrami

Also found another area with the same issue which looks even worse. Here is a screenshot of the normal map. 

final_fight

This thing happens to me when exporting unwrapped OBJ from ZBrush. It's like every uv island has different smoothing group.

final_fight

And this kind of retopo really looks like Zremesher work to me. With that polygon flow done by autoretopo there's going to be problems with UV seams.

musashidan

If you upload the high/low I'll bake it for you and at no charge.

whoever you paid for the retoo/uv 'work' just did a sloppy lazy 10min auto-job.

RashedAlmetrami

@musashidan  I'll upload it once I get to work, thanks! 

Jonathan85

there no "lazy" jopb even with auto retopo, believe me :-( it all takes fucking loads of time :-/

Anchang-Style

Would be really interested, once finished, how the UV Layout and retopo look like "correctly" done.

musashidan

Jonathan85 said:

there no "lazy" jopb even with auto retopo, believe me :-( it all takes fucking loads of time :-/

Believe you, eh? Thanks, I have clicked the Zremesher button quite a few times over the years.

yes, there are lazy jobs. So many new artists I see on these forums always complaining about doing manual work. It's part of the discipline. But those artists usually only get so far in their 3d journey. This is not an industry for those afraid of a little 'manual labour'.

musashidan

Anchang-Style said:

Would be really interested, once finished, how the UV Layout and retopo look like "correctly" done.

if you're interested in the basics of retopology and unwrapping, the wiki is a good place to start. What they would look like is a lot less triangles and a lot more texel res.

RashedAlmetrami

@musashidan We have managed to hide the seam somewhat but it would be good to actually know the reasoning for the seam. I've managed to find the scan data and will send you both tonight!

My assumption is that all the UV islands are orientated at an angle which is causing the issue? I don't think it's texel density as it's apparent on an 8k and even 16k texture.


Looking forward to finding out what's causing it!

Rob Samuel

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RashedAlmetrami

Yeah one smoothing group for both the Bake model and in-engine model

Rob Samuel

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RashedAlmetrami

@Rob Samuel I made sure smoothing groups were set by importing into and exporting out of 3ds max. 

@musashidan I've sent you a PM with the files. 

Looking forward to seeing it done properly

musashidan

Cheers mate. I'll have a look later when I get home

musashidan

I'm stuck working on a gaming laptop at the moment with only 16 gigs of ram and your file is a nightmare to work with. The high poly .fbx file is 6.5gigs, 50 million tris  and is pretty much unusable. It won't even load in zbrush and crashes/hangs Max. Even your 'low poly' is 200k triangles. Just a bit of pipeline advice: do not pass 6.5 gig .fbx files down the pipe if it is completely unnecessary. So due to that I was unable to do a test bake. 

Having said that, a quick look at your retop mesh shows your UVS are flipped/inverted. This is why that seam shows up, I'm betting.

Another piece of advice: don't work with the artist that did this shoddy and lazy(I should probably exchange the term lazy with amateur) work. It's pretty terrible and very unprofessional.

RashedAlmetrami

@musashidan Cheers, It destroys my PC aswell I sent you the RAW scan data which bakes out an Albedo using horrifying UV's. I would usually decimate the model for my own pipeline but the UV's/Albedo of the scan data needs to be intact to transfer the Albedo onto the Retopped model.

I'll look into the flipped UV's and will do a test bake just to make sure.. Thanks again!