This artifacts in the shadow are a reproduction of the objects in my testroom.
If somebody knew how to get rid of this, telling me would be appreciated
If you need some code i can post it, but I don't think its necessary since all I do is to add the shadows without parameters.
I'd say mandrav is on the right track here. Irrlicht doesn't do zfail in the case that camera is inside a shadow volume, so zpass is used all the time and that doesn't do shadows correctly in this situation.