No Altitude for extruded Buildings

[strech345]

Hey, because i use a elevation Modell i have to move extruded buildings in height. But it only use building height. I think the altitude parameters only works for geometry export. so, absolut and offset should be add to extruded export

[yaozhihang]

If necessary, we may consider adding this functionality to the KML/COLLADA/glTF-Exporter in the future release.

[clausnagel]

@yaozhihang We should add this to our feature list for 3.4.