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668 Chapter 12: Animation
ThesceneshouldhaveaFreecameratobe
match-moved, as the tracker does not create
one. The scene also should ha v e a set of Po int
or CamPoint helper objects positioned in
3D to correspond to the tracking features.
Optionally install the movie as an env ironment
map-basedbackgroundimageinthematch
camera viewport. This is needed if you want
to render a composite using the match-move
or checking match accuracy. This doesn’t
automatically display the background image in
the v iewport. Us e Views > B ackground Image
toselectthebackgroundmovieanddisplayit
in the viewport.
Real-world camera films a scene (the white dots will be
tracking points).
2. Open the movie file in the Camera Tracker
utility and create a set of feature tracking
gizmos for each of the tracking features in the
scene.
Resulting footage to be tracked and used as a background.
3. Position the Feature Selection box and Motion
Search box for each gizmo so tha t they’re
centered on the features and have motion
search bounds large enough to accommodate
the biggest frame-to-frame move of the features
throughout the frames that will b e tracked.
4. Associate each tracker with its corresponding
scene point object.
The associated scene point objects are set up in 3D space
based on real-world dimen sions.
5. (Optional)UsetheMovieStepperrolloutto
set the start and stop frames for each tracker if
it’s out-of-view for any of the frames that will
be matched. These specify the frame range
during which the tracker is visible in the scene
and will be t racked as par t of the matching
process. This mechanism allows you to match a