reponse du forum offi :
Due to the heavy modifications of the 3D engine, which now features advanced lightmap calculation using radiosity, dark areas without much light are much darker now.
Older maps might need a bit of rework to add a few blocks with lights unless this issue is possibly fixed.
Donc en gros problème déjà connu il faut attendre le patch pour réparer ça :p
Bon bin je vais garder le projet pour plus tard et refaire des circuit a ciel ouvert :o