Why & when I shall use Surface Tab in Mocha for After Effects

[Roland R. kahlenberg]

mocha uses its tracking splines to define planar areas for tracking. The Planar Surface is used to define transform related tracking data and corner-pin points for export to other applications. There have been lots of questions on mocha here (use the Search feature).

HTH
RoRK
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[Eric Mccarthy]

Basically, the X-Spline is used to denote the area that you want tracked, the surface tool is the area you intend to replace/effect. The two do NOT have to be the same. In one recent job, I had to replace a green screen monitor which was constantly being crossed or hidden from view by other elements in the scene. There was no time in which the entire monitor was viewable, and most of the time only about 33% was viewable. However, there WAS a desktop computer box that was ALWAYS in view. It was on a perpendicular plane to the monitor, but stayed in relation to the monitor during the camera movement. I used the X-Spline tool to track the desktop case, and after I had a good track on that, I created a planar surface for the monitor in the one instance that I could see all four corners. Sure enough, Mocha was able to keep my plane (for the monitor) by using the tracking data from the desktop box.
After exporting the corner pin data for the surface, applying it to a lower layer in AE and keying out the green, I had an image that was convincingly stuck on (under) the monitor, even as people crossed, etc.

I guess this is a long way to say that the X-Spline deals with the tracking data, and the Surface tool deals with the area you want to effect.

Lots of great resources here:
https://www.imagineersystems.com/videos?tagFilter=%25tutorial&sortBy=Newest

I am by no means a master, and I am only starting to harness Mocha, but I can already tell it is way better for this type of work than AE’s motion tracker.

Good luck!

[Suny Basu]

Hi,
Thanks a lot.

[Suny Basu]

Hi,
Thanks a lot for this tutorial.