[OBD U5] merged DV elements vs DEM cells

Hi,

Is there any setting to make a merged DV to retain the information relating to its original 3D elements, like DEM? At the moment when I merged a DV, all elements are blown to bits like what you'd get from a visible edge extraction. Where as with DEM, each 3D element will be converted each individual cell. 

Best regards,

Tuan Le