Generate Texture while KEEPING UV's from Retopologized Mesh?
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Hello,
I'm working on a model and wanted to know how to generate a texture that keeps the unwrapped UV's from an imported model.
Just FYI, my ideal workflow is: Generate model in RC > Export model from RC > Import model into ZBrush > Clean model in ZBrush > Retopo and unwrap UV's in ZBrush > Export model from ZBrush > Import model into RC > Generate texture while KEEPING unwrapped UV's from ZBrush.
I've read that it's possible but haven't found information or steps needed to accomplish it. Could anyone inform me on how to do this?
Any help would be greatly appreciated! If I missed a thread that discusses or lays out the process, could you point me to it? I've been searching for a while but haven't found anything yet. Or at least I've gotten close but they don't share the steps.
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That makes good sense, thanks for taking it further pushing models from ZB and RC to Blender. I agree on the need for an option in RC to set up axis, but that only covers what happens after the roundtrip through ZB, or even more importantly to me, in Mari, where it's nuts to paint on something lying on its side. If I got this right, you say ZB now supports setting up axis on import of FBX, but that because it's unable to control for left or right-handed, this isn't enough. No? I just poked around and found this in the Prefs:
Have you tried playing with whatever iSwitchYZ is or any other permutations of iFlipY and iFlipZ? None of these work? I'll try to play with that here too when I come up for air. I should note, RC users aren't alone in this lament, see posts from a Photoscan user in ZB complaining about the same issue. BTW, something else not making sense, you say you believe RC is X-up, which would be really off-map, but if this were the case I wouldn't be able to import RC meshes into Unreal with correct up axis as I do, and Unreal is Z-up. I just used my hands to simulate Z-up and Y-up left and right-handed, playing out what should happen in Blender to predict those values you show, +90 on the X, -90 on the Z, can't seem to get there from here ;^) Matters not. If we can get to a coherent view of the behavior and be sure about the proposed fix in whatever prefs in RC, that's our strongest bet to affect change.
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The import export preference settings is for obj format. I got no problem when using obj. Importing and exporting obj meshes between RC and Zbrush is straight forward, I actually don't need Blender if I'm using an obj mesh. BUT, as everyone knows, obj is 3x the filesize of an fbx and fbx is the most common file format that is being used in a pipeline and plus fbx supports camera export which is necessary for manual projection of photos outside RC. Those are the main reasons why I'm pushing the developers for a solution when using an fbx format.
The default import export settings on zbrush 2018 and 2019 should work fine.
The actual fbx import export settings can be found on the Plugins -> FBXExportImport, but for whatever reason it doesn't work at all. Any options that I select gives the same result everytime.
Well, now that you've said it, I'm not sure on the up-axis of RC. Yeah it could be Z. I actually based the up-axis on the color of the gizmo - red, which is X axis on all 3d programs.
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JM, I just spoke a friend, lots of ZB experience, though he's not sure about this, it being less relevant to his workflow for 3D printing. In any event, I see the pref in the Zplugin> FBX Export/Import for MayaUp, which is Y-up. This would seem to indicate that leaving it disabled defaults to Z-up, begging the question why a Z-up FBX from RC (if that's indeed the case) would import appearing on its side. Nick claims the default perspective in ZB is "looking down the barrel of Z", that is a top view, this because of the 2.5 D nature of ZB, an artist looking down on an artboard. This would also be like plan view for an architect. If this is the case, that would explain the behavior we're seeing. A good test would be to export a Y-up FBX from Maya, import it under both settings, see if that's consistent with this understanding. Nick claims there's a pref setting to control the default camera/perspective.
What still doesn't make sense, if RC and ZB are both Z-up, and if OBJ doesn't record up-axis into the file, why would an OBJ from RC drop in with different up-axis than the FBX, you'd think with no up-axis needing changing the absence of a recorded up-axis would allow the default Z-up world to pass through to ZB. Have you posted this issue or question on the Pixilogic forum?
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I did a few more tests on different scenarios but still getting the same results. I think I'm gonna stop on this and would just wait for RC update of having an option to change the orientation on mesh export.
Zbrush is definitely left-handed Y-up axis. Here's a good discussion about this, including other 3d programs:
https://blender.community/c/rightclickselect/HGbbbc/
http://archive.zbrushcentral.com/showthread.php?5481-Zbrush-Coordinate-system
For RC, I would think its X-up right handed. This problem still exists for quite sometime (almost 3 yrs) and still happening today, and the way things are going right now, no one seems to know which side is the problem.
I'll try to ask on zbrush forum, but I won't count on it as I also tried zbrush 2018 and still got the same result. I doubt its just a normal bug. Something is probably broken in between these two apps that requires them to sit down and talk.
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Hello!
Do not touch FBX! Even experienced 3DSMax and Maya users know how buggy FBX support in ALL apps. And zBrush was never had good support for FBX.
If you want use generate UV in external app, including zBrush, i highly recommend use OBJ. As proven interchangeable file format that using most of 3D scanning studios around the world.
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JM, I think Vlad's point may hit the nail on the thumb. Now that I think of it, I've heard this from other folks with way more time outside of RC about problems with FBX. I agree, it's a real shame having to deal with bloated file size and not bringing cameras along. At the same time, I'm not one to easily let go of a problem, see no reason to dismiss a possibility here; might it be that Autodesk's FBX format missed it on accounting for an important detail like left or right-handed in how that information is generated, passed through the file, and listened to on the other end? Vlad, when you say buggy, I hear problematic due to some random variable, but how certain are you that this couldn't be a case of something masking as random behavior, but in fact is predictable and based on incompatibility between two programs, RC and ZB in this case, where failure of Autodesk to account for something like left/right-handed causes the issue flipped up-axis? This issue, while real, seems at least consistently off, not random. Maybe, artists working in 3ds, Maya, Mudbox, ZB experience yet other issues unrelated to up-axis that indeed are "buggy", but it seems the only problem between RC and ZB in FBX is limited to up-axis, might be worth making a distinction? Appreciate your insights.
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Hey All,
Great thread - Quick question
Export model
Open external software to edit and instead of editing the mesh I build a new mesh
Then export
Reimport into RC for texturing
Will this work? I have some fairly basic shapes that are part of a larger scan like cylinders, boxes, and tubes. RC missed some geometry on them and I would like to just replace the meshes with simple models.
Also, a similar question. Can you bring any model into a RC scene and then "texture" it at any location? I know this would casue some strange texturing but will the software do this?
Thanks all!C
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