Shadow Issue - light seems to pass trough an edge

Hi all,
my name’s Pietro and I’m an italian 3D Artist.
I’ve been working with 3DStudioMax for years but I like Blender and I think that with 2.60 release it could be a serious alternative to max for my work.

But… I’m having a strange problem with shadow casting:
1 - I’ve made a floor (the bottom plane) and a roof (the upper plane).
2 - Both casts shadows correctly.
3 - If I make a wall extruding edges, the upper side seems to work ok while the one in the bottom has a serious problem: it looks like the two faces are not connected.

I tried really lots of combination before posting: flipping normals, detaching and solidifying faces, making blocks… no ones of these seems to work.

I’ll post some screeshots:

I’m using Blender Internal, no GI, no AO, no EnvLight, only a SPOTLIGHT and BUFFERSHADOWS.

Has anyone had this problem?

Thank you a lot,


Ok, I’m really sorry: I’ve been looking for the solution for about two days and obviously as soon as I’ve posted it I’ve discovered something new…

If I tune the “Clip Start” parameter I’m able to correct this issue.
I’ve changed it from [60cm] to [900cm] and now it’s working… even if I’ve got still a little error on a wall, but I feel I’m on the correct way.

Thank you, have a nice day!