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How can I UV a model when its subtools had been merged and decimated? Confusion in the workflow.

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Hi,
please take my apology if this had been explained already before but there is so much information out there that one can easily get lost and I am also new to Polycount.
I am very new to 3D modeling and ZBrush in  general and I have been trying my best with all the tutorials possible but I am still not getting very clear answer on the workflow of:
I have created a model of a character, merged down all its subtools to be able to decimate it and test it in Mixamo for rigging and animation (all works fine). At this stage I do not have any textures or polypaint on my model and I am standing in front of - what do I have to do now to create UVs and to be able to polypaint it? Is it possible to create UVs on decimated model which has eyes, teeth, clothes etc all in one tool? I have watched tutorials about UV Master in ZBrush and tested it but I am not sure if the UVs are good or not because it gave me quite a lot of pieces . Or do I have to go back to the high poly model before Merge down and do the UVs separately for each subtool? Would that work to then merge them down and decimate the whole model with UVs applied? is there any easy way to do this for a beginner?
I am sorry if my question is wrongly put together but that would probably just confirm my confusion on what am I supposed to do next.

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  • kanga
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    kanga quad damage
    Hi Lenka_Dan.
    What do you want the end product for/to do? Do you want to use the model in a game engine, or just for animations?
    It's not usual to rig decimated meshes, or to merge subtools before decimating them individually first. Depending on what sort of figure you are trying to make an end product of you will possible end up with a very difficult model to rig, texture and animate, even if you plan to use an auto rig solution. Probably the best thing for you to do is state what you want  to achieve in the end and why, and include some descriptive images of what you have now. It would be useful for you to take a look at the wiki to get a better idea of the process. You can find a link at the top of this page.
  • sprunghunt
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    sprunghunt polycounter
    You can UV a decimated zbrush model but you'll need to use a 3d modeling program like blender, maya, or 3dsmax. 

    The lower polygon the final result is, the easier it will be to UV. 
  • Lenka_Dari
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    Hi,
    Thank you very much for both your answers.
    I will try to clarify a bit better what I am trying to achieve and support it with some images.
    The model I have been working on is to be used in a short animation (for a college project). The model won't be seen all the time on the scene but when it will be, I have to show some movement, for example door opening or short walk. My model was about 3Mil polys before decimation (clothes included), after decimation it dropped to 150k polys and kept fair amount of detail thanks to Decimation Master. I needed the lower poly model to be able to animate it later on in Maya without causing my PC to burn down :). So I brought it to Mixamo to test the movement and I am quite happy with it so far but as I mentioned that is a model without any texture or colour on it. On images bellow I am showing the seems on back and front of the character. I used the UV Master and painted the areas to Protect and Attract and I tried it several times, this was kind of OK result I got from ZBrush. (I know it is not ideal). I applied texture map and I am also showing the terrifying result of unfolded UV map in the last image. I am aware that these are not nice UVs but it worked on merged and decimated model. Question is now, if I would polypaint on this will that work? Or do I have to go steps back before the decimation and go through a completely different process? Should I first do UVs on all subtools of the model and then merge it all together and then decimate? Wouldn't that change the Uvs then?
  • Lenka_Dari
  • kanga
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    kanga quad damage
    Ah ok. You can polypaint the decimated merged model in zBrush and export it, probably best as fbx to Maya. From memory you have to have the colorize button (polypaint menu/ tool shelf) active in zBrush for the export. That will export the painted vertex colors. For vertex color you dont need uvs.

    Normally you would decimate the model and clothing, export it to Maya, retopologize it, uv the lower poly version and bake and texture it in Maya, You can also export the lowpoly to substance or the free app xnormal (or another texturing app) there are several ways to paint textures, but the model will be easier to animate.
  • Lenka_Dari
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    Hi kanga
    thank you very much for your advice, this makes it a bit easier to understand now. I have also seen people creating UVs from polypaint and that might be also the case for me. If I don't need them at all that will probably make it a bit easier. Hopefully that will work with Mixamo and then Maya.
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