Zbrush/Blender to Ogre3d workflows

[gbbishop]

Hello first time poster longtime (3months) reader.

In short I want to outline a workflow for using these two programs to out-put a useable model for ogre3d. With as much detail as possible. Perhaps with the communities help and input I would be able to generate a tutorial as a way of saying thanks.

I am an artist by vocation and a collective of friends and I have recently embarked on a project using ogre3d for our engine.

For this I learned to model in Zbrush, as it was the easiest transition for me as a sculptor IRL. I have enjoyed learning Zbrush and can see the potential for great things.

That said, the 3D world is a beast. I have started to learn blender; I have heard it is as good as 3ds and maya but it is free.

One of your members Jerky, in 2006, sites his workflow thus:

Step 1: zbrush - initial modeling
Step 2: blender - for retopo/refining and UVs
Step 3: zbrush - detailing for normal map
Step 4: ???
Step 5: Profit...

This is a start but it leaves a lot of unanswered questions for me as a noob.

- How far do I push the initial model before exporting to blender?
- What needs be done there before exporting back to Zbrush?
- Does it need to go back to blender for .mesh-ification?

Thanks for listening I look for

[spacegaier]

- Does it need to go back to blender for .mesh-ification?

IT-guy here, so not much of help in regards to the actual modelling, but in regards to exporting: I am not sure if there is an Ogre exporter for ZBrush. But Blender has one (in fact multiple). So probably best to export from ZBrush to Blender and then from there to .MESH.

[gbbishop]

This is my understanding as well. I am okay with using blender for the final out-put. Just hoping to get some expertise to stream line the learning process.

[duststorm]

Most professional game studios use 3D max for getting their models inside the game engine.
A typical character workflow for a studio like Naughty Dog (Uncharted) would be:
- Create character base in MAX/lightwave
- Export from MAX to Zbrush/Mudbox
- Sculpt details
- Export from Zbrush/Mudbox back to MAX (eg. as obj wavefront)
- Import in MAX/Lightwave and retopo, rig, ...
- export from this editor to game engine

Anyway, you can replace Lightwave/MAX freely by blender, for which there is a .mesh exporter too.
Wavefront .obj is a pretty good format for moving a static mesh between programs.
I advise you to rig your characters in the tool you're going to be exporting from (in this case Blender).
A normal/displacement/occlusion map can simply be baked to a texture, so in the final step you just export an .obj from blender to Zbrush again, bake the maps (you'll be sticking to the same UV map), save them as images (eg. png) and you can use them in Blender.

As for a few of your other questions:
- You can go as crazy as you want with sculpting details. Just be aware that small detached things like small hair strands will be problematic if you want to end up with a reasonably low poly model.
- In the retopo process you will be determining what the polycount will be. Of course the higher it will be the more detailed, but your baked maps will take care of a lot of detail too. So you basically try to tweak your polygon counts so that they are denser in areas where the maps would fall short.
- I believe your UV maps should match for baking. So you should probably use a retopo tool that maintains UV coordinates (I believe blender has such a tool).

Like I said, most professional studios use this same approach, and features of MAX/lightwave are fairly similar to Blender. Have a look around the web for tutorials or articles that describe this workflow and you'll get a better idea of what to do.
Naughty dog has some interesting slideshows of presentations and articles floating around on the net.

[gbbishop]

Killer Duststorm!

Thanks for your help.

That seems like a great place to start.

I will now be detailing these steps; expanding upon them and delving into specifics.

Why would you develop a base-mesh in max/blender? Zbrush, with the use of zsphere, seems to be way more intuitive. At least for me as an artist.

Any reason you could not develop the entire model in zbrush then export to blender for retopo and UV mapping?

Would this be a viable workflow?

-Develop/detail model in Zbrush.
-Export .OBJ to blender to generate UVs
-Import UVs to Zbrush for paint and texture (would likely use PS as well)
-Export .OBJ to blender for retopo and rigging.
-Use one of the ogre exporters to get a .mesh

Where and when to I add the UVmap files to the .mesh? They appear to be separate files (in the sinbad file) at least as far as I can tell.

Am I missing any thing crucial?

[duststorm]

Why would you develop a base-mesh in max/blender? Zbrush, with the use of zsphere, seems to be way more intuitive. At least for me as an artist.

Any reason you could not develop the entire model in zbrush then export to blender for retopo and UV mapping?

I think it's a viable alternative. As to the why: not sure. Maybe because modeling is often done by other people. Maybe because those editors already exist for much longer and most artists are already used to working with them for years (Zbrush and widespread use of 3D sculpting is a lot more recent). Maybe because classic 3D editors still offer more tools for modeling. I'm not sure exactly.

I use Blender for everything, modeling and sculpting, so I automatically have a more integrated workflow. I'm not really experienced with ZBrush.

Am I missing any thing crucial?

Baking normal maps, displacement maps and ambient occlusion maps maybe? Once you retopo your model in Blender, I think you should export it back to ZBrush (with matching UV coordinates) so you can bake the maps.
Of course you can also do it in blender. The important thing is that you have the two models (sculpted hi res and retopoed) in one tool so you can bake the maps.
Normal and displacement maps go into your shaders directly, ambient occlusion can be used to create a diffuse color texture. Multiply the ambient occlusion (AO) with your regular color texture to give it some diffuse shading (for example in photoshop or the gimp).