Geometry opacity

Hi vvvvolks,
I’m new in shaders and have a (maybe stupid) question:
I’m working with a pack of Box (Geometry) and no matter where is placed my camera, the boxes are always transparent. I just can’t get a right depth with foreground boxes hiding background ones. I guess that’s normal given that the problem is the same with all shaders, but is there a solution to reduce that phenomenon?

Thanx vvvvery much for help


look here:

Oh… it was as simple as this? what a shame… Anyway, thank you kalle, that’s much better this way!