i was just demonstrating that almost anything is
possible one way or another in revit.. but as far
as shadows with no elements being visible- only
under certain condition can you even do it and it's
far from any kind of practical revit process.. it's
almost like an "artifact"- certain views with a
certain camera angle and it happens.. but
it's hard to pin down exactly what causes it..
sorry if i mislead you because this is really not
something revit does..
but i will be thinking about some of the kinds
of anomalies that causes it to happen and
post more about here later after i understand
more about it myself..