one chunk from multiple photo sets tutorial what if background changes though ?

[Steve003]

Hi,
https://agisoft.freshdesk.com/support/solutions/articles/31000155265-how-to-build-a-complete-360-degree-model-of-an-object

great tutorial on using multiple photo sessions of different sides of an object and combining into one chunk for better results, but how is this done if the camera was moved round the object then the object turned upside down and another photo session done, then another of a related part that had broken off.

Steve003