2009

You should make the feature bounds box large enough to enclose the feature
and some of the surrounding images enough to give the feature a contrasting
background of several pixels.
The motion search bounds defines the are in which the feature will be searched
for from frame-to-frame. This bounds box moves with the feature box, so the
area is relative to the current feature at each frame. It’s important to estimate
this search area well. If it’s too large, the matching process will be unnecessarily
slow and there’s more chance of other features in the search area making the
search ambiguous; if it’s too small, tracking errors will occur. It might be useful
to review the movie that will tracked on a real-time playback device like a
video deck and estimate feature moves beforehand. If you set the Max
Move/Frame spinner to the maximum move before creating the tracker, its
motion search bounds box will be set to accommodate this move for you. You
can also adjust this box at any time in the Movie window.
NOTE It’s possible to change the search bounds box for different frame ranges
in the movie, so you can optimize your search capabilities. See
Keyframes and
Position Data
on page 3841.
Working with the Movie Window
Displays the current frame of the movie being tracked and any active tracker
gizmos for that frame. You can open and close the window using the Display
Movie check box in the Movie rollout or minimize it using the standard
window title bar controls.
When you first open a movie, 3ds Max sizes the window so it will fit on the
screen and this might result in an automatic zoom out if the image is too big.
You can resize the window by dragging its sides or corners. You can zoom
around in and out of the window using the tracker gizmo controls.
3828 | Chapter 15 Animation