For this scene in Sony's "Spider-Man 2" we were tasked with removing the Monofilament wires attached to all of the moving lights and flaps in the background behind the lead actor.
This is the original plate photography for the scene. Notice that the lights flicker with different tonal values throughout the scene. This made things very difficult to simply paint out the wires. Instead I made the difficult choice to rebuild the entire background using a series of stills. Each still representing the 35 different tonal values. I built 35 "clean" frames and cross dissolved between them to recreate the flicker.
Part of the problem with rebuilding the background is the fact that the camera tilts down in the middle of the shot. To solve this I crafted an intricate morph between two clean plates, to recreate the camera move. (The above yellow lines are not a 3D model, these are the tangents that guide the morph.)
Once the background was rebuilt and the lights and flaps were rotoscoped, we rebuilt all of the drop shadows cast by all of the moving objects in the scene.
Lastly, the lead actor was rotoed off of the original background so that he could be overlaid on to the rebuilt scene.
Much to everyone's annoyance, Sony neglected to inform us that they had put a huge CG set piece in front of the removal. This essentially obscures about 90% of the work that I and my colleagues had done over the past 2 months.