Using a 360 capture and a modeled floor (what's the best way of stiching them together)

How can I create a whole scenario in which I have a 360 capture as surroundings and the floor is modeled? A bit like Holotours for Hololens.

The idea is to have a 360 capture of a room, but being able to add elements to the room itself, and have the stiching of the 360 with the floor seamless.