Quick UV/Zbrush Question...

[Elfenlied]

I've never really understood normal map workflow, so can someone please explain it to me?

Here is how I understand it...

Step 1. Base Mesh (Maya)
Step 2. Scuplt (Zbrush)
Step 3. UV Map Base Mesh (Maya)
*Step 4. Export the Normal Map from Zbrush to Maya.*
Step 5. Apply the Normal Map
Step 6. Use the Normal Map to make a color/diffuse/etc maps.
Step 7. Light Scene
Step 8. Render

My main question is:
Do I UV Map the model before or after zbrush, because I'm doing lots of armor and I'll be having multiple mesh extracts, I don't know how that effects the UV maps and therefor the normal maps?

If you don't understand I can try and explain better...

Thanks in advance! :thumb:

[mike_fowler]

There are a couple ways you can go about this workflow Elfenlied.

If you're starting with base meshes from an external app, my workflow would be

> Base Mesh in Maya (no need to unwrap UVs)
> Sculpt in Zbrush
> Switch to lowest division level in Zbrush and retopologize using Zbrush's re-topo tools
> Export your new re-topologized mesh into Maya and unwrap. Once unwrapped, export back into Zbrush.
> Divide the new re-topologized mesh to an appropriate number of levels to support your hi-res sculpted details.
> Project the highest division level of your sculpted mesh onto your new re-topologized mesh.
> Export lowest division level (or the lowest level which remains under the polygon count you're shooting for) back to Maya

After that you have a couple options. You can generate your normal and AO maps from within Zbrush using Zmapper on your highest division level, and then apply those to your model in maya and use the AO for the texture as an overlay layer.

The second option, and preferable for me, is to export your highest division level from zbrush, and then use a program like xNormal (http://www.xnormal.net/1.aspx) to generate your normal and AO maps based on the difference between your lowest and highest division levels. xNormal supports 12 million polygons or more, so using your highest division level shouldn't be an issue. In my experience xNormal generates crisper and cleaner maps than zbrush does for hard surface objects like armor or architectural elements.

I would really recommend going through this re-topology tutorial, it explains the concepts extremely well. http://www.jcappelletti.com/z3tut03/

The reason for not unwrapped your object before starting your sculpt is that if you're making major changes to your mesh during your sculpt, your UV's are going to get distorted anyways, thus it's better to sculpt first and then re-topo based on lowest division level of your final sculpt.

Let me know if I can clarify anything, but that tutorial should help clarify most questions.

[Elfenlied]

Hey Mike,

Thanks so much! That is exactly what I needed. :thumb: