Tracking with MochaAE

Now that we have filmed the footage with the phone displaying a green screen it will be possible to track a pre-comped animation of our app into the shot footage. The first step in doing this was to trim down the footage using mpegStreamclip so that only the minimum frames required are left, this is because tracking can be time consuming and wasted tracked frames will slow things down. Once the clip has been trimmed down it can then be imported into the After Effects project and placed in a composition, the option 'Track in mochaAE' is then selected to open the clip in mocha.

Once the clip is opened in mocha an X-Spline layer is created of the phone and a planar layer is added. This is then tracked forward frame by frame automatically with some manual corrections, this then generates corner pin data to be used by After Effects.

The corner pin data in then copied into After Effects and applied to the app pre-comp, making it match the movement of the phone in the shot footage. Once it has been lined up the Keylight effect is then applied to get rid of a specific green channel, letting the app animation display through the shot footage:

Overall I'm really happy with how the track came out. Although the reflections on the screen made it far harder to track I think it vastly improves the realism of the final shot.