I have a Raster DTM at around 400 m. I have aligned shapes to terrain. So my shapes have all a different altitude. Around 400 meters. Yes i'm trying to make an accurate representation of real buildings, wich I know their top altitude.
I would like to extrude buildings at 420 m for example. Ok I can extrude 20 m. But how to use the altitude ? How can I get the altitude of the shape ?