Each point sample contains {TAIL ~ 3D coordinates} in {HEAD ~ a 3D coordinate system}, as well as colour and intensity information 
Each point sample contains { TAIL ~ 3D coordinates } in { HEAD ~ a 3D coordinate system } , as well as colour and intensity information
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH