3d shape: height of buildings: height roof polygons - height ground polygons?

Discussion created by nabla on Jun 25, 2011

first of all, I'm an absolute starter using GIS software.

I have a 3d shape which includes polygons of the "terrain" and polygons describing walls and roofs. The polygons are differentiated inside the attribute table. Using the 3d anlyst, I can get the height of the polygons, which is what I need. However, I guess the value is the height above sea level. I need height of the roofs above the ground! So, just heigth roofs - height bottom... But how do I realize that?

All ground polygons completely cover the region I'm interested in. They consist of triangles filling the region. Reading through the manual, I found that there is something like a terrain. Maybe that terrain does the job. However, I was not able to create a terrain from the polygons I have.

Any idea?

Thanks alot!