ZBrush Workflow
So, I have a few questions about ZBrush. I've been modeling for awhile and I spent most of this year studying computer science at Northeastern University. I want to get back into 3D for the summer. So, I'll just lay down my questions.
1. I'm familiar with exporting a model to ZBrush and sculpting with it but can someone explain retopologizing to me? How to do it and how does that translate to steps taken afterwards. For example, once it's re-topo'd, how do you get the normal maps exported and working (3ds max in this case). At what stage of lowpoly -> highpoly -> retopo do I unwrap the model's UVs?
2. Also, I've seen some pretty good textures that were said to have been done through poly painting in ZBrush. How do you do this? Are there any good tutorial videos involving this? And, relating to above, when would I unwrap the model in relation to doing this?
Any answers or links would be of great help, thanks.
And as a side note, generally what brushes do people like in ZBrush for just forming the shapes they want; I'm talking high-level here, not minute details. Thanks a lot!
-Kyle
1. I'm familiar with exporting a model to ZBrush and sculpting with it but can someone explain retopologizing to me? How to do it and how does that translate to steps taken afterwards. For example, once it's re-topo'd, how do you get the normal maps exported and working (3ds max in this case). At what stage of lowpoly -> highpoly -> retopo do I unwrap the model's UVs?
2. Also, I've seen some pretty good textures that were said to have been done through poly painting in ZBrush. How do you do this? Are there any good tutorial videos involving this? And, relating to above, when would I unwrap the model in relation to doing this?
Any answers or links would be of great help, thanks.
And as a side note, generally what brushes do people like in ZBrush for just forming the shapes they want; I'm talking high-level here, not minute details. Thanks a lot!-Kyle
Replies
http://www.3dworldmag.com/page/3dworld?entry=tutorial_files_for_3d_world9
http://eat3d.com/zbrush35_intro
http://www.topogun.com/
In a nutshell, here's how the process works.
Once you're done with the high poly, use decimation master to get the poly count down to a reasonable size. Import that mesh into topogun for the low poly. Once you have the low poly, export the obj to max and do the UV's. Once you have the UV's done, import your decimated mesh into the same scene in max and using the render to texture feature create your normal map. You can use the normal map to create an AO map (using RTT again). You can skip the max part and reimport your UV'd low poly into the lowest subdivision of your zmesh and reproject the higher level detail (it asks on import). Once this is done, you can create your cavity, normal, AO, and polypaint maps. This can be problematic in that zbrush tends to monkey with the scale a bit. Make sure you freeze xforms before you bring your base mesh into zbrush, and that your export scale in Z is set to 1. There's a great plugin you can use called gomax that handles import and export between max and zbrush pretty well. You can get it here:
http://www.zbrushcentral.com/showthread.php?t=81506
To enable poly painting you have to UV the model. If you're using a low poly you created in topogun and UV's in max you don't have to redo them - they'll come in by default. If you're using an unUV'd model you can auto UV it in zbrush by hitting the GUVTiles button in the UV Map submenu in tools. There are settings. I'm not sure what the best ones are, but you can poke around as good as I can. When you're done with this, expand the polypaint submenu and turn on colorize. At this point you can begin painting. You'll want to turn off Zadd and turn on the RGB button. Grab a color, an alpha, and a stroke, and you're good to go. Once you have the texture looking the way you want it, expand the texture map submenu and click new from polypaint. Then hit clone texture. This will place the texture in the texture menu at the top of the page. From here you can flip it if you need to and export it. If you were painting on a model with proper Max UV's, you can apply the texture directly to your low poly. This is the workflow I prefer. If you're using a autoUV'd model you'll have to export that model into max and RTT the textures onto the low poly model.
These are my main brushes:
flatten / focal shift -42 / brush alpha 28 / intensity ~15
clay / focal shift 0 / no brush alpha / intensity ~15
move
inflate
hpolish
dam_standard (not included but great for tight crevasses, get it here)
smooth / intensity varies of level of detail
Let me know if you have any more questions.
1) realy basic shape modelled in max/maya. exported to zbrush (not unwrapped at all)
2) sculpt that simple shape into a highres. export highres
3) retopo highres in zbrush, export that as the low
4) unwrap the low you exported from zbrush
5) bake the high onto the low (outside of zbrush)