A bizar problem with directional light PLEASE HELP


The problem is very simple to explain:

The direction vector of directional light doesn’t have an effect in software. It works great in full hardware acceleration mode, but in software, even if I insert a direction vector of ( 0,0,0 ) it doesn’t have an effect and act like its a static lights illuminate down the Z axis.

Have an idea ???

Thanx, Itzik.