Hey,guys. I'm working on a small project these days with 3d compositing in AE but get stuck.
I shot some small boxs on the table (with green screen under the objects)using some smooth camera movements just tilt and pan.
Now, in the AE, keying is OK. I wanna use another image for the 'table cloth'. I tracked the small boxs and create a null object, and parent the new 'table cloth' to the null obj. I found that the new'table cloth' do move with the small objects, but it doesn't change the scale as the small boxs does.So it looks bad.
And I'm not sure whether it is the correct way to composit a background with original green-screened videos.
Any idea, how to solve it?
Mocha Tracking allows for a Corner Pin Export which will be best suited for this kind of project. I think this can work for the table cloth since it is basically a square object. However, if that does not work, you may need a 3d tracker- like camera Tracker from the Foundry, or Boujou, that will allow for a true 3d track and then you can position a 3d textured layer for your table cloth.
However, there should be no scale influence from a 2d pan or tilt. Basic AE or Mocha tracking should suffice. The boxes and the new BG need to share the same perspective is all. But, if you actually moved the camera in 3d space then a 3d tracker will probably be neccessary to get the shot spot on.