Exporting 3d shapes from CityEngine to ArcScene

I have a 3d city model in CityEngine and exported it to ArcScene (Multipatch Features). Then i would like to float the shapes on a DEM. The problem is, that i can not float it on that DEM in ArcScene...i can only put a constant value, which is not helping me.

How do i export it correctly from CityEngine that i can float in in ArcScene?