The best way to UV pack low poly model for bake

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Veezen polycounter lvl 4
Hi! Right now I make UV map of my low poly model for baking process. The worst part of my workflow because I spend on this a lot of time and I would like to learn new way of UV mapping to speed up this part. I have a lot of UV islands for perfect normal bake (hard edges = new UV island) and to improve my texturing I trying to arrange these UV island near the rest of object. I don't like to use automatic pack, because it's not work the way I want.

I know about IPackThat but this is quite expensive at this moment, and I don't think it would be work like I want.

Any tip will be very usefull.

Replies

  • Eric Chadwick
    Show an example of what you have so far, with the texture. Hard to critique your workflow without an image to judge.

    These might help you
    http://wiki.polycount.com/wiki/Uv#UV_Tutorials
  • WarrenM
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    WarrenM Polycount Sponsor
    iPackThat will pay for itself within a few uses. The time it saves MORE than makes up the money it costs...
  • Mark Dygert
    There can be a pretty significant difference between what bakes/packs well and a layout that is painting friendly. If you do a lot of painting, you can use two separate UV channels. UV1 bake/packs well, UV2 painter friendly. Then transfer UV2 to 1.

    I tend to do this with ultra low poly meshes that are mostly diffuse only, with little to no baking and a lot of detail painted into the diffuse. But I only do that if it's hard to strike a balance between painter friendly and an optimized layout.

    With a high-low work flow, I tend to unwrap and texture the high poly in a way that will give me a decent start on my materials. That layout can be whatever it needs to be to make the materials work, which are usually tiling materials like wood, concrete, leather ect...

    This works out great because the tiling materials, including their normal, diffuse and spec all bake down to the low poly which can be highly optimized and hard to paint on. But the patterns like wood grain flow perfectly across the islands. So instead of trying to use Photoshop to get wood grain to flow across separate islands, you just bake it and some of the distortion is handled for you, which can be really helpful.

    You can also use techniques (on the high poly) like Neil Blevins blended box mapping to eliminate seams, on the high poly.
    http://www.neilblevins.com/cg_education/blended_box_mapping/blended_box_mapping.htm

    I'll then use viewport canvas to paint masks or overlays directly onto to the model in the viewport. Again, it goes to the optimized
    HighLowBaking.jpg
    The point I'm trying to make, is that these don't need to use the same UV layout, you can use whatever layout works best for each step and then transfer it to a layout that works best for the final result. If you get good at unwrapping you can do it pretty quick and even faster if you use tools like ipackthat.

    I really enjoy unwrapping and I've gotten pretty fast at it so I don't spend that much time unwrapping and packing. I tend to do a lot of "Quick planar map", cylinder unwrap and basic techniques, like stitch, point to point edge selection to draw seams, break and relax. I did two layouts for the coffee table above and I spent 10min on the first and 20 on the final. it helps that it's mostly easily planar mapped rectangles.

    The default packer in 3dsmax kind of sucks when it comes to complex concave shapes but packing a selection of similar shapes can be helpful.

    Good luck, I hope my rambling helps!
  • Bek
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    Bek polycounter lvl 5
    Veezen wrote: »
    I have a lot of UV islands for perfect normal bake (hard edges = new UV island)
    But also remember that new uv island = seams = more difficult to texture — so if you can spend more geo to minimise on seams and still get the nice shading for normal map purposes.. :thumbup:

    But yes if saving time is your goal IPackThat seems pretty great.
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