Ah okay,I was using cg_shadows 6 ^^
Thanks again for your explanations TreB 
EDIT: I tried recompiling the map and I don’t get the exact same result as you, my lightmaps look bull****,and my bsp file is much smaller, also ingame the tree is almost totally lit while in yours the backfaces are correctly shaded, dunno if it has something to do with my low quality lightmap…
<-- my compile
<-- your compile
I think you used special commands or something, I tried changing samplesize but it does no difference, my lm_0000.png is pitch black and my lm_0001 makes incredibly small squares for the walls. I use the q3map2build tool in the etxradiant folder and run “NORMAL” compile on all stages.
Thanks in advance for your help and explanations TreB 
Btw the trees are killing my fps, when I use r_showtris I see it is ruled by CPU calcultation(in red right?), I though using r_vbodeformvertexes but it doesn’t changes it.