You want to have the same character interact with an exact duplicate of himself in the same shot.
Here is an example and how I would tackle it in After Effects:
The Synopsis
I want the same character, sat at each side of a table having a conversation (Lets say Mr A and Mr B). Mr A halfway through the conversation will pass a glass of water to Mr B who will pick it up and take a drink.
The Shoot
At first I would film Mr A having the conversation on his side of the table, and have someone of-screen reading Mr B's part for timing. I would leave 2 seconds gap between Mr A finishing his part of the conversation before Mr B has to speak. At the same time I would record the sound of the take on a separate device*. Half way through Mr A would pass the glass across the table - once done I wouldn't move the glass, just keep it in the same place for Mr B's take!!
Now I would film Mr B on his side of the table, and listen to the previous recording on the separate device* then signal to Mr B to say his parts of the script. Remember the timing/part of the script where the glass is passed across by Mr A, I would give it a few seconds and have Mr B pick it up and take a drink - before filming this take, I would do a few dummy runs because if something fowls up after Mr B picks up the glass, it means filming the part of Mr A all over again! :x
While filming both shots:
I would make sure there is a clear space/gap between Mr A and the glass and Mr B and the glass when filming.
Also that when filming the actor looks in the direction/empty space where the Mr? will be sitting.
The Edit/After Effects
Depending on the sound recording I may have to delete/lower levels on Mr A's take where the person was reading the part of Mr B of-screen.
I would first sync both clips up conversation/timewise. Then just box mask Mr A's clip down the middle, making sure to overlap the glass on Mr B's take (This should show Mr A and Mr B at the table with the glass on Mr A's side). Hopefully the few seconds gap between Mr A putting the glass down and Mr B picking it up, would give me time to move the box mask across following the arm of Mr A (This should now show Mr A and Mr B at the table but this time the glass near Mr B). I may have to create a more detailed mask around the fingers. If I really wanted to be clever I would have someone walk passed the table on one of the takes, but this would mean a lot of detailed masking! :shock:
I know I have gone on a bit! and this may not be the idea you have... but this is the way I would tackle it in After Effects.
http://www.grafxflow.co.uk/forum/
