3D buildings from osm to kml

oh, thanks for advice. I found solution.
download area in osm format → convert to obj with osm2world → convert obj to kmz with SOLA G2.
One question only. How to calculate center coordinates of my area to specify in SOLA G2 options???
and how to convert heavy osm files to obj? tried osm2world.sh -i a.osm -o b.osm and it’s working for 2 hours already.(osm file is 1.5gb)

upd. after 150 minutes osm2world aborted with out of memory error…