So
What kind of camera?
Can it be remote triggered?
I suppose you would have to look for change in Z in g-code
May have to get slicer to insert command in g-code output
to indicate "new layer" then trigger macro
I don't use pronterface -- old CAM
Repetier with Slicr or cura much better
Just capture all of it with usb Cam and edit it
or use motion trigger available in some cam software