So it is, thankyou very much!
Hi !
Sorry but I can’t just uncrease my mesh , I just did it as you said and nothing happen , the smooth groups are staying 
you need to hold shift, or alt, or ctr when uncreasing (I forgot which as not used ZBrush for couple of months)
As Spittle says, SHIFT+click the Tool>Geometry>Uncrease button to remove all creases.
You can also specify the Crease Level before dividing the mesh so that creasing is removed above that subdivision level. Set the Tool>Geometry>CreaseLvl slider.
I just did it as he said and nothing happen
It doesn’t work at all
You will only see an effect when you divide the mesh after uncreasing. The mesh won’t change otherwise, apart from the creases will not show as dotted lines. To see creases you must have polyframes visible (Shift+F).
It would help if you posted a picture showing the problem you are having.
My mesh is already subdivided to the 7th level and I can’t subdivide more , how can I uncrease it and keep the details i’ve sculpted on it ?
Why do you want to uncrease your model at that level? It won’t make any difference to the sculpting if you are not dividing further.
It’s because I want to generate my normal map only where i’ve sculpted something.
http://s2.noelshack.com/old/up/rugerexplanation-1ee2ed7a73.jpg
If I can uncrease and keep my sculpting details , maybe it will work , but I just can’t uncrease
What you need to do is:
- Go to the lowest subdivision level.
- Store a morph target by pressing Tool>Morph Target>Store MT.
- Import your original model through the Tool>Import button. This will restore your base mesh.
- Generate a normal map. This will be correct for your original mesh and will use the sculpting of the highest level.
Important Note: If you want to continue sculpting or generate texture maps from a higher subdivision level then you should press Tool>Morph Target>Switch before leaving the lowest level.
HTH,
Thanks for trying to help me , but it hasn’t changed anything , it still generates the whole normal map while it should only generate where i’ve sculpted something , if I knew that the smoothgroup import plugin would bring this kind of issue , I would have never used it
Don’t know if the plugin maker read me , but I’m sure that I’m not the only one who would like to see this issue fixed in the next version of the plugin 
It is nothing to do with the plugin. All that does is crease the edges of the groups as they are specified by the ‘s’ tags in the OBJ. It doesn’t affect normal map generation.
There’s a step I forgot which will probably make a difference in your case:
3.5 After you re-import your base model SHIFT+click the Tool>Geometry>Crease button.
4. Generate the normal map.
This may sound perverse but try it.
It’s worse because every face appears on the normal map generated now
Thank you very much for trying to help me , but it looks like desperate 
OK, try one more thing. Go to the lowest subdivison level and switch the morph target so the the smooth group-creased mesh is restored, then generate the normal map from that. That will only have your sculpting in the normal map because it will be generated for the creased mesh, not your original.
You may find that you get a better map with Adaptive turned off. And don’t use Smooth UVs.
It doesn’t work , i’ve tried everything , with cage and without , import with the plugin and without , switch with the cage or without
Can you send me the model? I’ll generate a normal map for you. You can send it to marcus(a)pixologic.com - that’s with the (a) replaced by @