3D Tracking Data

3D Tracking Data

Many people don’t realize that After Effects can import
Maya scenes (.ma fi les); but they have to be properly
prepped and include only rendering cameras (with translation
and lens data) and nulls. The camera data should be
“baked,” which is Maya parlance meaning that it should
have a keyframe at every frame (search on “baking Maya
camera data” in the online help for specifi cs on this).
3D trackers operate a bit differently than the After Effects
tracker. Generally you do not begin by setting tracking
points with these; instead, the software creates a swarm of
hundreds of points that come and go throughout the shot,
and it “solves” the camera using a subset of them.
Besides Position and Rotation, the Camera may also
contain Zoom keyframes. Unless Sergio Leone has started
making spaghetti westerns again, zoom shots are not the
norm and any zoom animation should be checked against
a camera report (or any available anecdotal data) and
eliminated if bogus (it might be a push or even an unstable
camera). Most 3D trackers allow you to specify that a shot
was taken with a prime lens (no zoom).