(Foundation-1) number of surfaces: 6
1) bsm_Mainfloor2
( 1 2 3 4 )
2) bsm_Mainfloor1
( 4 3 5 6 )
3) bsm_Mainfloor4
( 6 5 7 8 )
4) bsm_Mainfloor3
( 8 7 2 1 )
5) slab
( 1 4 6 8 )
6) to_main
( 7 5 3 2 )
