Just an idea:
select a point inside the volume near the hit point ( e.g. adding the inverse normal). Now trace upwards. You can check this result for:
the trace hit nothing: it was an outer level wall
the trace hit a backside face: it is a block with a topside check the value wether it has the required height
the trace hit a frontside face: no clue what happens at this point
muffel
Last edited by muffel; 06/24/11 22:04.