I'm curious if it is possible to create or extend a Jib move with footage using camera mapping. the footage was shot following a car down a highway from above. as the car passes underneath the camera the camera flips upside down and follows (panning to it, not physically following it) the car. there's a lot of movement in the footage although other than it being a nodal pan the camera is relatively static. what i would like to do though is create a jib move that drops closer to the ground while still retaining the original nodal pan. i understand how to camera map using a picture but I'm unsure about the approach I will need to take to get what I am looking for here. thanks.
It sounds to me like this would involve similar techniques to those used in upconverting 2D footage to 3D. You want to recreate the same scene, but from a slightly different perspective.
As the camera drops lower, parallax will cause the car to move higher in frame relative to the highway, revealing more of the road surface underneath it, and obscuring more of the road/horizon above it.
You'll need to model stand-in geometry for the road, the car, and any other objects in the scene that would exhibit visible changes due to this parallax shift.
You'll also have to decide how to deal with the newly-revealed areas, most notably the section of the road under the car. As you drop the camera down, the texture projection will actually project the image of the car itself down onto the road surface, and the camera will see this. You can fix this in one of two ways: either create a 'clean plate' of the highway, with no car visible, and project that onto the highway, or do your 3d render with the doubled texture and then clean it up in the comp stage afterwards.
That's a quick sketch of how you might approach it... other people may have other suggestions. Good luck.