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Zbrush Workflow

breyz
polycounter lvl 8
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breyz polycounter lvl 8
Hi,

Could use some advice. I made a lowpoly in Modo, didn't UV, took into Zbrush and detailed. Took a heavily decimated version back into Modo and UVed it. UV came out... ugly. Took another decimated version into Modo, but a hipoly this time, baked normal from it to the heavily decimated. Normal map was shit...

How should I go on about this, really? If I UV the lowpoly before I take it to Zbrush, can I make a normal within Zbrush on that UV? If so, that's probably what I should've done.

But now that I did not do that, and I've already detailed my lowpoly in Zbrush, how can I save this project without starting over with the detailing?

Replies

  • Stinger88
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    Stinger88 polycounter
    dont worry.

    Export your low poly and UV it in which ever software you chose. Then you can import it back into ZB and you can project the detail from your high poly detailed model onto your newly UV'd low poly.

    I haven't watched it all yet. But I think this tutorial shows you how to do it.

    http://www.veoh.com/watch/v1404129GHfEeJ4r

    TIP: remember to project the detail at each sub division level starting from the lowest.
  • cryrid
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    cryrid interpolator
    Personally, I would only use decimation master for preserving surface detail, so that I can import what would otherwise have been a very high-poly mesh into an external program to bake a normal map without my computer melting. I would never use the decimated result for something that would be game-ready/UV'd.
    If I UV the lowpoly before I take it to Zbrush, can I make a normal within Zbrush on that UV? If so, that's probably what I should've done.
    Yup, on the Tools pallette there are several palletes for generating texture/displacement/normal maps. Generally you click the desired button to create the map (such as 'create normal map'), followed by the clone button to clone the result over to the Texture pallete where it can be exported.
  • breyz
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    breyz polycounter lvl 8
    Thanks :)

    Do I have this right?: Whenever you have a 10+ million poly tool, you have to make the normal map in Zbrush, because there's no way to get it to Modo with all its detail and bake there, if I decimate enough to actually bring it into Modo, most of my fine detail is lost anyway, so baking a normal map after that is pointless.

    Argh, so confused...

    I'll try to describe my problem and what's confusing me:

    Say I've made a low poly mesh and UVed it, I take it into Zbrush and detail it. But here and there it's not just fine detail, the shape of the mesh changes a bit, like some places where I've hacked away pieces of a concrete pillar. Now, I could make the normal map in Zbrush, since I have already brought in a UVed model. But it wouldn't look very good unless I do some changes to my lowpoly mesh to better reflect those cuts in the concrete pillar, I have to add a little bit of detail to the lowpoly. But then my UV isn't the same, and then my normal map made in Zbrush is reflecting a different UV? WTF?

    I must be retarded or going about this so backwards.

    As long as I've planned in great detail, and know that I won't change the mesh so much that the lowpoly needs changes, just add fine detail in Zbrush, that's fine.

    But what if you just want to create something in Zbrush, and then retopologize/make lowpoly, how do you go on about that? The UVs and creating normal map from that 10+ million mesh you've got in Zbrush.

    I understand Zbrush can create UVs, but those UVs aren't very good for games application are they? And they're a bitch to paint on.
  • Stinger88
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    Stinger88 polycounter
    You dont have to make the normals map in ZB just because the polycount is high. I spose it depends on what your computer can handle. I know I cant get more than 2-3 million in maya on my aging computer.

    You could try Xnormal.
  • Will Faucher
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    Will Faucher polycounter lvl 12
    Stinger88 wrote: »
    You dont have to make the normals map in ZB just because the polycount is high. I spose it depends on what your computer can handle. I know I cant get more than 2-3 million in maya on my aging computer.

    You could try Xnormal.

    I was just about to suggest this. You don't even need to open the file in xNormal. Just identify where your HP mesh is located on your hard drive, and BAM! It shits out a sweet normal map for you.
  • cryrid
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    cryrid interpolator
    Say I've made a low poly mesh and UVed it, I take it into Zbrush and detail it. But here and there it's not just fine detail, the shape of the mesh changes a bit, like some places where I've hacked away pieces of a concrete pillar. Now, I could make the normal map in Zbrush, since I have already brought in a UVed model. But it wouldn't look very good unless I do some changes to my lowpoly mesh to better reflect those cuts in the concrete pillar, I have to add a little bit of detail to the lowpoly. But then my UV isn't the same, and then my normal map made in Zbrush is reflecting a different UV? WTF?

    There are 3 basic components to this whole thing: the mesh you start with, the high-poly sculpt, and the mesh you want to use in the game. Sometimes the basemesh and gamemesh can be the very same mesh, and sometimes they are two completely different things.

    If they are the same, just drop down the the lowest subdivision in zbrush and export it. Now you'll have the lowpoly mesh that includes any major changes to the form that occured during the sculpting process. Zbrush doesn't tend to care about UVs, so you can always change them at any point in the process. If you want you can export the lowest level once you're done sculpting, give it a new set of UVs, and then reimport it and zbrush will automatically update the UVs for you while keeping all of the sculpting that you did.

    Sometimes you don't want to use the same mesh though, as the basemesh might be very basic, and/or its topology was built with sculpting/subdivision in mind instead of animation. Maybe you didn't even have a basemesh and just sculpted from something like zspheres or shadowbox. If this is the workflow is basically along the lines of:
    1. Make basemesh (no UVs needed)
    2. Sculpt it, polypaint too if you want
    3. Retopologize to final game mesh, UV that
    4. Use zbrush or external program (xnormal/max/maya/softimage/etc) to transfer the details
  • breyz
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    breyz polycounter lvl 8
    Thank you very much everyone, this clears up everything! No longer confused. I've had a long break from this and couldn't even remember my old Zbrush workflow, getting old...
    Now that I think about it, I never got down a good workflow for it, but I will now. Now that I understand the options I have.
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