I don't have experience with 3D Coat, but with the UV Master plugin UV generation and normal map generation are very easy in ZBrush.

Jibb

I'm lazy tonight
Do you have some advices, tutorials for UV mapping and normal map creation ?

I found that great post for retopology (works great) !

Zbrush Retopology

UV Mapping tutorial. Once you've retopo'd and created UVs, subdivide it until you can project all the original details (it's good to "Project All" at every division along the way to keep the whole shape from having to change much), then go back to the division level you want to export and in the Tools Palette is a "Normal Map" button. Here you can generate a normal map. ZBrush will generate the normal map for the current subdivision level based on the highest subdivision level.

You can generate normal maps for different division levels. You can also generate an AO map by masking by AO and then doing a colour fill. This way it is very easy to generate multiple LoD levels and appropriate mapping for each one.

The UV Mapper doesn't give much freedom, but usually I prefer its fast workflow over the great freedom but long work of other tools. Also, generating LOD's this way doesn't give you as much control over the higher LoD levels, but it is fantastic for workflow. For me, it's exactly what I want.

Jibb

The problem for retopology is that i have that un SubTools palette :
- Object 1 : High poly model
- Object 2 : Z sphere Retopology

And i don't know how to say : Ok bake the high molde on the low poly retopo ??
Same thing for Uv's i don't know how to make them on the low poly retopology ?

I'll have to dig it up !

In the sub-tool palette there's a "Project All" button, which projects one sub-tool onto all (or maybe just all visible) other subtools. Select your low-poly retopology and click "Project All" (you probably don't need to, since you would've built it on-top of the other model). Then subdivide, and use Project All on the higher subdivision. Keep going until you have all the detail you need.

ZBrush doesn't bake normals by tracing from a low-poly model to a high one. It does it by getting the normals of the highest-subdivision mesh and projecting them onto whichever subdivision you have selected when you generate the normal map. It's not what I was used to, for sure, but with the freedom to sculpt extra details into the high-poly version of the retopo as you see fit, it's easier IMO to make a flawless projection.

For making UVs, if you have UV Master the video explains it in detail. But the basics are: select your model, open UV Master, click "Work on Clone" (or something like that), "Unwrap", "Copy UVs", then go back to your original low-poly model and click "Paste UVs".

Jibb

For my case things are more complicated to bake normal map.
And importing in 3D Coat made artifacts i don't understand ??
Perhaps polygons inside the model due to the Merge on Subtool
i made ?
I'll go lot more fast by redoing entirely the model on 3D coat,
now i have the concept in 3D

And Retopology under Zbrush is really far from all the options
and easy fast way you can do in 3D Coat !

For the workflow between 3D coat and Zbrush i'll have to do some tests to find the better !

It's earlier WIP, lot of thinsg to polish !
All to redo
It was so fast under Zbrush !

Can't you just devide it into two parts in ZBrush? And import the two parts in 3DCoat?
Or, a better solution, cut it in two halfs, you can mirror the half in 3DCoat anyway - at least, I guess so.

In fact the problem is really strange, and i think comes from
all "glued" parts in subtools !
I've been able to import it all under 3D coat the first time, but normal map baking done really strange problems like i showed it

Another test :
Under Zbrush i made one whole model, no several parts, with on subdivision only , and imports perfectly under 3D Coat and 3D Coat bakes normal map perfectly also :



Like you can see on picture i made some precise curve in upper subdivision , with this precision i think i can do lot
of things in Zbrush-> 3D coat workflow !

So last thing to do, Redo all the goblin in Zbrus using only one or two subdivision on base mesh !

--------

That's strange but i find lot more easy and fast to use
ZSpheres for main body, hands etc ... + Zsktech to make quickly all the shape ... compared to 3D coat Voxels !
Only my personnal taste !
This little character roughly done , only took me some 15 or 20 minutes trying things (Zsketch -> Flatten tool to quickly
make all smooth, than Claytubes mainly ) !
Yes Zbrush is fast !!


So my workflow will be one whole model under ZBrush, than
import in 3D coat for fast Retopo, UV , normal map making and painting !

3 subdivions on Zbrush and painting som details on surface !
Import in 3D coat is ok beacause is OK and normal map is without artifacts afetr retopology :

We can see all details i put in Zbrush are ok on the normal map of low poly begin !




The first Zbrush goblin i made can't be re used caus i deleted
lower subdivion levels to gain further levels of subdivision

But it will be fast to remake it one time in Zbrush !