User Manual

 Steady: After analyzing a planar surface, this mode removes all motion and distortions
from the planar surface, usually in preparation for some kind of paint or roto task, prior
to “unsteadying” the clip to restore the motion.
 Corner Pin: After analyzing a planar surface, this mode computes and applies a
matching perspective distortion to a foreground image you connect to the foreground
input of the Planar Tracker node, and merges it on top of the tracked footage.
 Stabilize: After analyzing a planar surface, this mode allows smoothing of a clip’s
translation, rotation, and scale over time. This is good for getting unwanted vibrations
out of a clip while retaining the overall camera motion that was intended.
The last three modes (Steady, Corner Pin, and Stabilize) use the tracking data produced in
Track mode.
NOTE: None of the operations can be combined together. For example, both Corner
Pin and Stabilize cannot be done at the same time, nor can a track be done while in
corner pinning mode.
Reference Time
The Reference Time determines the frame where the pattern is outlined. It is also the time from
which tracking begins. The reference frame cannot be changed once it has been set without
destroying all pre-existing tracking information, so scrub through the footage to be tracked and
choose carefully. The reference frame must be chosen carefully to give the best possible
quality track.
You choose a reference frame by moving the playhead to an appropriate frame and then
clicking the Set button to choose that frame.
Pattern Polygon
You specify which region of the image you want to track by drawing a polygon on the reference
frame. Typically, when you first add a Planar Tracker node, you are immediately ready to start
drawing a polygon in the viewer, so it’s best to do this right away. When choosing where to
draw a polygon, make sure the region selected belongs to a physically planar surface in the
shot. In a pinch, a region that is only approximately planar can be used, but the less planar the
surface, the poorer the quality of the resulting track.
As a rule of thumb, the more pixels in the pattern, the better the quality of the track. In particular,
this means the reference frame pattern should be:
 As large as possible.
 As much in frame as possible.
 As unoccluded as possible by any moving foreground objects.
 At its maximal size (e.g., when tracking an approaching road sign, it is good to pick a
later frame where it is 400 x 200 pixels big rather than 80 x 40 pixels).
 Relatively undistorted (e.g., when the camera orbits around a flat stop sign, it is better to
pick a frame where the sign is face-on parallel to the camera rather than a frame where
it is at a highly oblique angle).
If the pattern contains too few pixels or not enough trackable features, this can cause problems
with the resulting track, such as jitter, wobble, and slippage. Sometimes dropping down to a
simpler motion type can help in this situation.
Chapter – 107 Tracker Nodes 2408