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UV mapping question

Hi all.

Most of you who are working with 3d programs knows how big pain in a** is Uv mapping, it kills creativity it is slow and everyone wish there would be a magic button to fix it.

My question is, we have a automatic unvrap is program such as blender or maya where you can unvrap at 1 click and you are good to go so with this tools why modern GameDevs still prefer to do it by hand ? I know we have a tons of this small sh** comming in uv editior and it can be a problem to find out what is where but after all it is ok, substance painter works fine with it. So what is a problem is there some steps further in game engines such unreal or unity where this uv is a nightmare or it is only a fps performance issue?

Why we still do uv mapping by hand? What is a reason people still stick to uv by hand?

Replies

  • pior
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    pior grand marshal polycounter

    Because clean (or, clean enough) UVs are just as important as clean enough geo. If you believe that the process is is a pain in the ass, then that just means that you haven't yet gotten used to creating your geo while thinking about your UVs all at the same time. If you do, all your seams will be planned and placed as the geometry gets built, and the final steps of the unwraps will be trivial.

    As a matter of fact something much worse than having to work on UVs ... is to deal with modelers who don't understand how to craft clean UVs and thinking of it as "last step". This always ends up costing precious time.

    Also, some art styles are dependant on the way UVs are organized (modular environment modeling, toon shading as done by ArcSys, and so on). So the more you avoid the topic by hoping to get it fully automated, the less versed you'll be in these creative/outside the box techniques.

  • rexo12
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    rexo12 greentooth

    The reason is that auto-uvs are generally a bit crap. In particular they don't understand the orientation and flow of your surfaces that well. I've learned that everytime i've been lazy and auto-uv'd something, it's just made more work for me when baking or texturing. They also yield substandard density.

    I do use autopacking tools to help me pack my islands, but usually with restrictions like no rotation or packing only a certain area of the UV space.

  • iam717
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    iam717 polygon

    i like uving (my stuff) it is calming when you are not rushing every bit of the process to a stressful level, so if this is "studios" ridiculous time-frames of uving "hate" then i get it otherwise it is nice. I only ever learned how to u.v. in max and this is where i enjoy it, i can see if the program/s being used makes it a nightmare. pm me & pay me to uv your stuff i'll do it if the price is right? my example uv's are the wattedge character on 1st profile.

  • Cl3m

    Hello everyone !😀

    I have a question about uv optimisation in the uv editor for my game asset.

    I have a texel density 2048 and as you can see there is a empty space. Do I have increase texel density ? (Knowing that the résolution is correcte and I could increase it later at the baking stage.

    About the padding, I can't increase the padding more than, because I will have bledding between uv.

    How would you do to have a good optimisation ?

    Thanks for you help.

  • kanga
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    kanga ngon master

    pior: Because clean (or, clean enough) UVs are just as important as clean enough geo.

    rexol2: The reason is that auto-uvs are generally a bit crap.

    iam717: i like uving

    Nuff sed.

  • iam717
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    iam717 polygon

    Might as well add a possible solution for them also, @Don_Wasyl : when i disliked or wanted to get to the texturing already and didn't care about the uv's, (old model or doing texture tests) i just hand made the seams where they needed to be (about 5 minutes), pretty quick in max (again only program i learned the most in) auto unwrapped them with the "relax" functions on top of each-other (5 mins for all) (usually 99% good enough), made quick obj's to import into zbrush, then used zbrush to "auto pack it" all nicely and fix any issues (1-3 minutes) with the relax re-exported and was done as far as i cared when i didn't want to do u.v.'s. (15 minutes or less)

    Hope it helps alleviate the situations till you become very comfortable with doing u.v.'s once upon a time i too disliked it but made it a "challenge", to get good or really good at it with the packing,re-arranging, and density so it became a little game to me, "puzzler", now doesn't bother me. Like modeling hands,feet do, once you got good ones no need to ever do it again, unless a concept has some wacky design.

    @Cl3m i am weird (i guess) anything too small i want to make bigger, so anything that needs extract detail or will be the main focus I'd increase then repack around that. (hopefully someone who does props can chime in and tell you more.)


    edit:#2 here if you didn't see this: https://blenderartists.org/t/uv-packer-for-blender-free-windows-macos/1287541 idk if it helps or you tried it i just found it so i popped it in here.

  • Kanni3d
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    Kanni3d ngon master

    TD on unique assets does not (and most of the time cannot) need to be perfect. Feel free to size up small parts larger to take up space and give it some more resolution, as they are inherently tiny as @iam717 suggests.

    There's flexibility in either direction of texel density, usually texel density is only "off" ifit is noticeable by eye, not the calculated number.

  • Cl3m

    Thank you for your answer @Kanni3d, I can continue my project ! 😁

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