Building - Roof height above sea level

[mphaneuf]

Guys,

I'm playing around in AIM, and everything looks pretty cool, except for one thing I do not seem to understand: the Roof Height Above Sea Level checkbox. Every time I check this box, the buildings in my model seem to disappear and cannot find them. If I uncheck it, they reappear to the right location.

The Building layer is set to drape over my terrain, with roof height set to number of storeys * 4, and roof slope to 10. I do not set an elevation offset. 

Thank you for your help,

Maxime

[konstantin.baumann]

Hi Maxime,

the "roof height above sea level" flag can be used for datasets which use an absolute value (above sea level) for the roof height of a building, which is independent from the actually imported ground surface.

Suppose you are dealing with a building dataset which uses a roof height of "2000" meters above sea level (since the building is located in the alps) and you import a terrain surface which has a height level of about 1970 meters in the region around that building, then the building will be constructed with a building/roof height of "2000 - 1970 = 30" meters. Note that buildings with negative roof height will not be generated (which probably happens in your case).

Therefore, since you said you use "drape on terrain" this checkbox will not work for you...