A computer reconstructs a virtual 3D table layout from tv camera pictures in real time and they can pan around it at will. BBC outside broadcasting is as slick as it gets. It can be done from a single fixed position. It's particularly useful to show viewers a players or referees eye view of whether a ball is snookered or not etc, or how different a shot looks from the baulk end. The camera at the top of the table gives a false impression of how easy or hard most shots look.
Believe me, the red may only be one foot from the pocket, but it is all too easy to misjudge or misdirect the cue ball when playing from the bottom of the table. If it was as easy as they make it look we'd all be world champion.
Boro Nut