Packing Tools with non-uniform scaling?

LuckyNinja · Jan 2018

Hey there, I've been getting back into modelling after a couple years' hiatus (making good on all the free student versions of stuff while I still can), and that's left me considerably out of the loop tech-wise. I'm wondering if there's any UV unwrapping / packing tools that give the option of allowing for non-uniform scaling, or 'weighting' UV islands. I'm working on a model where certain parts will barely be seen, and thus would like to scale them down further so I can have higher resolution on the more visible parts. I know that all great UV maps include some degree of manual adjustment, so I'm not asking for a quick fix per se, but I'm hoping that there's some software or plugin out there that can let me hit the ground running, so to speak.

Cheers!

gnoop · Jan 2018

Usually 3d packages could pack island without re-scaling them , so you can scale them manually to what you think is ok and then pack. Keep in mind that varying texel size within same texture could make you problems in soft like Substance Painter. So a good idea probably is to unwrap and texture with consistent texel size first to a hi-res master file and then re-bake it to optimised "weighted" final unwrap. It does help to get better impression on environment modelling where texture budget is never enough.

LuckyNinja · Jan 2018

Interesting point about texel size interaction with Substance Painter. It's one of the things I got the student version of, and alongside Designer fully intend to learn and use in my pipeline. Can you elaborate on how it could cause problems?

gnoop · Jan 2018

Not that it's absolutely impossible. There is triplanar projection after all.

Still in many cases where UV input is in use to generate/scale procedural features it would create corresponding inconsistent size and feature stretching based on your "weighting". Even non-square textures are somewhat a problem.

Projection painting allows to workaround the issue too but it's not especially convenient in SP

Axi5 · Jan 2018

I wonder whether some method involving an ambient occlusion style calculation to control the texel density would work. It would obviously be a custom plugin but my first thought of an automated algorithm that decides what scale to have a certain polygon is, would be "how visible am I?". If it's hidden in a nook or cranny somewhere then it's worth less texels, hence why I thought some variant of an ambient occlusion style calculation would be handy.

I certainly think it's possible to create this, but to be honest these days most people just keep the texel density consistent and use tiling textures. As @gnoop says, the procedural features of substance would basically ruin the look of most models with uneven texel densities.

profz · Jan 2018

sorry if it's too late to answer but in maya 2018 you can set texel density by going to UV Toolkit window and in Transform section you can find this

Image: https://image.prntscr.com/image/pDP_WVTIQP6V3SRp5C3CLg.png

select one of the island/shell in your UV and click "Get" button to use your selected island as sample for texel density value. and "Set" button will change texel density on your currently selected UV based on current texel density value on the tool

or you can use unfold3d too, i've seen many awesome featues on the trailer

https://www.youtube.com/watch?v=nqHM8WRnSkM&t=1s  > on the comment section, the ts said you can set texel density too

Packing Tools with non-uniform scaling?

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