CompuServe Messages

I've read in the most recent edition of LWPro that shadow maps will still see an objects 100% dissolved. Is this true? I've used shadow maps and it seems to me that an object dissolved 100% is invisible to a shadowmap. Maybe it isn't for anything short of 100%. I have a set that has a cieling on it with the normal pointed down so that camera could see it if it happened to tilt up enough. I had placed a light above that cieling, pointing downwards into the set. The light is shadowmapped. When I first started out I was having problems because I did not realize that the object, "self shadow, recieve shadow…" buttons were only for traced shadows and did not affect shadow mapping. My shadow-mapped light source was totally blocked by the set cieling. Once I set the cieling object to 100% dissolve my problems seemed solved. Of course I could just remove the object from the scene, but it hasn't been necessary. Can any one comment on this? Bruce