High resolution to low resolution workflow, for animation. How do I do it?!

ch0bra

Hi everyone, I've never posted here before but I'm at my wits end and hoping I get some good advice. Apologies if this is in the wrong section, I wasn't sure. 

So basically I've recently decided to learn Zbrush, whereas I would have always worked in maya before. I plan to use a maya - zbrush - maya workflow, in that I create my base mesh in Maya, sculpt and paint in zbrush, bake my normal maps etc, then export my low res model to maya and apply my normal map and textures. As far as I know this should work in theory, but every time I get to maya for rigging and animation, my models have lost a huge amount of painted detail, and the sculpted detail doesn't look nearly as good. The UV maps I've used for my high res and low res models are the same and they seem to be working okay but the textures just do not transfer well enough at all. I've also tried experimenting with a displacement map (couldn't figure out how to apply both that and the normal map in maya 2016, with v-ray) but haven't achieved much success. I created my texture using polypaint in Zbrush and my normal/displacement maps were created in zbrush as well. I've used xnormal before also but I had similar problems regardless. I've tried with v ray materials and standard materials and there doesn't seem to be much of a difference in either of them. Someone told me to look into using substance painter but as I've never done so I'm not even sure where it would fit into my workflow. I've searched online endlessly for answers and there doesn't seem to be a specific one.

Really what I need to know is: Is a workflow like this possible and/or efficient? What am I doing wrong? Does anyone know where I could find a tutorial course that would teach me a proper high res to low res workflow for animation? I'm tearing my hair out, as I'd planned to be learning rigging and animation by this stage but instead I'm stuck trying to get my models production ready. I'm including an image below of (left) my high res model in zbrush and (right) my low res model in Maya, with the material and normal map applied. Absolutely any advice welcome and thanks in advance for your time.

unit187

Afaik Zbrush's polypaint is basically vertex coloring, means when you reduce amount of geometry, there are less vertices left, therefore less precise textures. What you want to do is to export your highpoly model to XNormal and bake vertex colors into textures. 

But yeah, you should pick up some tutorial course, because you are trying to reinvent the wheel here I think 3dmotive has some outstanding courses covering whole process, check their web-site, some cool stuff over there.

ch0bra

@unit187
Thanks man! So if I bake the vertex colours into the textures using xnormal, that should see me lose less quality in the actual texture then? That could very well be what I'm missing! I managed to get the normal map to look a bit better but with the colour depreciation it still looks terrible! 

I'll check 3dmotive out! Actually never been on that site! Hopefully I can tackle this and move on, thanks very much for your reply!

ch0bra

Not sure how I quoted the above but it would appear I can't delete it! Aw well haha. 

MagicSugar

Textures in zbrush viewport is not 1:1 to what you'll see in maya's viewport or quick render.

You'll have to modify the textures in a tool like photoshop as well as tweak your maya shaders.  Search for tutorials that include Zbrush render passes and baking matcaps (the native zbrush shaders that you use with your polypainting won't just transfer or export without additional prep work).

ch0bra

Thanks very much! I'll look into these things! Hopefully see some improvements today! 

kanga

• Set  up the scale of your mesh so that it is at the correct size in Maya and the best size in ZBrush using the export dialog at the bottom of the tools palet in ZBrush
• Model and detail your mesh in ZBrush (doesnt matter if you use a base mesh from Maya or one you made in ZBrush).
• Paint you model in ZBrush
• At the highest subdivision level decimate a copy of your model in ZBrush: 1-1.5% poly level should work fine
• Send your decimated copy to Maya 
• Model you lowpoly model over the decimated template making sure there is no interpenetration of polys
• Uv the lowpoly in Maya
• Apply a projection cage (not sure about this in Maya but in Max it works well).
• Export the lowpoly plus projection cage using  the xnormal option to a disk
• Export an .obj of your high poly at its highest level to a disk, remember to check colorized is active under the polypaint palet in the tool palet
• Open xnormal and point it to your lo and hi poly models
• Check baking options in xnormal and cook
• Use png for normal maps and uncheck vertex coloring  on the hipooly for the AO map

Thats it, well one way to do it. I never had much success with baking maps in ZBrush and all I really need it for is modelling, sculpting and painting. The way above lets you use a fully detailed model at its highest rez to bake from without having to have it open in any application. Where substance and apps like DDO come in are the production of PBR maps which will blow your mind in any game engine.  On your model there isnt any props to speak of but you could import the model and the diffuse maps and power them up in say substance painter. If you want the model for games stay away from displacement maps. You could use height maps but you will need a heavy rig to work with them in an engine. For high(er) poly animations you can produce displacement maps with xnormal.

Hope this helps

There is a series of these and they are pretty darn good: http://eat3d.com/character_lowres