Movable mesh dont fully dark with a DirectionalLight

Hello,
It’s been a long time that I get stuck on this problem I can not fix.
Do you have any suggestions?

Thank you for your answers.

It looks to me like those objects are being effected by shadows properly. Are you expecting them to be darker?

Of Course, the area has no light at all, the mesh should be darker.
The foliage tool seems be the problem :confused:

Can you please provide steps for how we can reproduce a scene that matches yours?

Yes, I have do a small video : Inesquivable - Light problem ? (27 june 2016) - YouTube |
http://image.noelshack.com/fichiers/2016/26/1467058919-1.jpg