Workflow for creating UVs from High Poly Object with Polypaint from ZBrush ?

[Daimon]

I'm trying to understand the precise, step by step workflow for creating UV maps in 3d-coat after importing a high poly mesh with polypaint from ZBrush.  For example, what importing method should I use - Model for Per Pixel Painting? - or what room to open it up in - Sculpt Room?  Do I then autoretopo the mesh and then export/import in order to apply the UVs to the mesh?  And how or where/when is the polypaint image applied.  I did manage to use autoretopo before and draw the seams, but I am not certain if I export and re-import will the UVs be attached.  Thank you in advance.

[Carlosan]

Hope it help

[TimmyZDesign]

First import the high poly with polypaint from Zbrush into the Sculpt Room using the "import for vertex painting" option.

Then go to the Retopo Room and import the low poly there. (So then you will actually have the two different versions of the model occupying the same space). You can however only edit the low poly version in the Retopo Room. If you don't yet have a low poly version, then use the manual retopo tools in the Retopo Room toolbar to make one. Then make your UVs on the low poly. There is a full set of UV tools in the Retopo Room toolbar, but they are context sensitive so some might not be available at first. Alternatively you can Autoretopo and AutoUV, but oftentimes good useable results are difficult to achieve. Then from the Retopo Room choose to bake your vertex paint (a.k.a. polypaint) to the low poly and that's how you will send it to the Paint Room. There are various bake options in the Retopo Room's menu, but you most likely want to do a "per pixel paint" option. Then your low poly model will finally be in the Paint Room. Go to the View menu and turn off "show voxels in the paint room" to see only the low poly version with the polypaint baked onto it. Lastly go to the Paint Room File menu to Export Model to send your model out of 3D-Coat with its texture maps.

[Daimon]

Carlosan - Thanks for the referral!  AlienMinefield's thorough introductory tutorials on 3d Coat were immensely helpful and I would highly recommend them to anyone not familiar with the app.    I followed most of his workflow (see outline) and managed to export the model with textures to 3ds Max.   

 

TimmyZDesign - I tried your workflow but unfortunately had issues from the outset.  For example, initially I downloaded the high poly ZBrush model using "import for vertex painting" from the File, but invariably it would open up in the Paint Room. And now, for some unfathomable reason I can't even do that anymore, unless I use "import for vertex painting/big reference" which I doubt is what you meant.  As for importing the low poly into the Retopo Room, a pop-up appears asking if I want to save the high poly model which is in the Paint Room already.  As mentioned above, I was successful in using the Autoretopo to generate a low poly mesh with attached UVs.  Obviously I'm missing something in your instructions and would be curious to know what precisely it is.  Regardless, thank you for your answer.

 

1)  Downloaded the high poly ZBrush model using Autoretopo in Retopo Room.

 

2)  Rendered seam lines and unwrapped mesh.

 

3)  In the Bake option using "Bake w/ Normal Map (Per-Pixel)".

 

4)  Exported the low-poly model with textures to 3ds Max. 

[TimmyZDesign]

Yeah I think video tutorials are always the best because they show all the little detail steps that can't really be covered clearly in written instructions. So, I'm glad you were able to achieve what you wanted from those videos.

Sometimes however I've noticed that some users on this forum just want a quick written explanation instead of a video series, so I figured I'd provide you with that in addition to the videos Carlosan provided you. That way you can use whichever best suits you.

I think maybe one of the main things you missed with my written instructions was:

In the beginning you need to import the high poly model into the Sculpt Room. If you actually go to the Sculpt Room first, then import there, then the model will be imported into the Sculpt Room. However, once imported, you can see it in the Paint Room too because 3D-Coat will let you vertex paint (polypaint) just like in Zbrush if you want. Therefore you will see both the high poly in the Paint Room and also in the Sculpt Room at the same time. This can be confusing for new users because it is not clear that your low poly with UVs isn't actually in the Paint Room until you send it there by Baking it, but strangely you can already see your high poly model sitting in the Paint Room! In fact, I think this is actually one of the drawbacks of 3D-Coat because an imported model will sometimes only exist in one room, while it doesn't exist in any other room, but other times it exists in multiple rooms at the same time, depending on what you are doing. This makes 3D-Coat different from most other 3D apps, because once you import a model into most other 3D apps, then that model is available to you at all times (in all "rooms") no matter what you are doing with it.

Hopefully that makes my instructions more clear to you. In any case I'm glad you figured out what you needed! Best wishes!

[Daimon]

Sorry for being so obtuse over this whole procedure, but I definitely would like to try your method as well.  There seems to be a variety of options in both the File and Menu bar for downloading a model; so perhaps if you stated specifically where to download for both the high and low polys from, I could get a better handle on your workflow.  I did manage momentarily to have both the high and low poly in separate rooms but when switching between rooms, one of the models disappeared.

[TimmyZDesign]

Here is a tutorial (with pictures) showing my workflow for bringing a polypaint object from Zbrush into 3D-Coat, making retopo and UVs, baking the polypaint onto the retopo, and finally exporting it all back out of 3D-Coat. Of course there are other ways to do it, but this workflow works best for me in most cases.

 

Step 1:

I am in Zbrush and I just finished polypainting my model. I didn't bake it down to any UVs yet:

 

Here you can see the model is very high poly and subdivided to millions of polygons:

 

Here you can see the polypaint on the high poly mesh:

 

So now I export the OBJ out of Zbrush with the polypaint info stored in the OBJ:

 

Step 2: Now I open 3D-Coat and simply close the initial workflow choices pop-up. Then I go straight to the Sculpt Room.

 

Step 3: While I am in the Sculpt Room I go to the File menu and choose to import the OBJ that I just exported out of Zbrush earlier:

 

Now the OBJ is in 3D-Coat:

 

If I turn on Wireframe in 3D-Coat, I can see that the poly count is still very high:

 

Step 4: Now I go to the Retopo Room:

 

Step 5: In the Retopo Room I import the low poly version of my mesh. My low poly version already has UVs.

 

The low poly mesh is imported and sits directly on top of the high poly mesh. The UV seams are bright green lines:

 

If you don't have a low poly version of your mesh yet, then make one with the retopo tools in the Retopo Room:

 

After making your retopo mesh, then make the UVs with the UV tools in the Retopo Room:

 

Step 6: Now I Bake the polypaint onto the UVs of the Retopo mesh. I go to the Bake menu and choose "Bake with a normal map":

 

Step 7: Now I go to the Paint Room to see how the baking turned out:

 

I can see that my textures were created and put onto layers in the Layers Panel:

 

When I look at the mesh however, I see that it looks strange. It looks strange because I can still see the high poly mesh underneath the low poly mesh:

 

I need to go to the View menu and turn OFF "Show Voxels in the Paint Room":

 

Now it looks ok. I only see the low poly mesh in the viewport now. I can see the polypaint was baked onto it.

 

Hmmm, maybe it doesn't look very high res...that's because I chose 2048 for the texture size, and all of my UVs are on one tile. Maybe I will redo the bake in the future and increase the texture res, or use multiple tiles, but for now this will do.

 

If I turn on Wireframe in the Paint Room (View menu), then I can see the low poly wireframe of my mesh:

 

Step 8: For now I am done with texturing, so I will send the low poly OBJ out of 3D-Coat with its textures by going to the File menu and choosing "Export Object and Textures":

 

The End.

[Daimon]

TimmyZDesign.  Just wow.  I can't thank you enough for all your help and how thorough your reply was in delineating your workflow.  I'm certain it will be referenced by many in the future.  Unfortunately I can't share images of the rendered low poly object (can't access my gallery, grrrr), but nonetheless I'm extremely pleased with the results. And you are correct in claiming it is better to use one's own low poly model as opposed to autoretopo to generate maps; the difference was evident.  Also, I did export the model to 3ds max and the results were somewhat satisfactory - the texture was sort of flat, even after I tweaked up the normals to see more texture.  Alas, that is another question for another post or forum.  Regardless, thanks again for all the time and effort you put into your reply.  It is much appreciated.

[TimmyZDesign]

Glad to help!