Tracking a Pattern that Disappears
Tracking a pattern that disappears is easier
to do when the Fixed option is off. However, the results may not
be as accurate because any small errors you make in positioning
the tracker box are compounded when Fixed is off. Leave Fixed on
when possible.
To
track a pattern that disappears:
- Go
to the last keyframe before the reference point disappears.
- Click
Snap to redefine the reference point on this frame.
- Select
Add in the Edit Mode box.
- Ctrl+Shift-drag the tracker box
to the required position in the current frame.
Use the reference image you see in transparency
as a guide to find the new position. A keyframe is set and the timeline
advances one frame forward or backward when you release the pen.
The direction of the timeline depends on the setting in the Direction
box.
NoteIf you do not see the reference image in
transparency, set the Opacity option in the Setup menu to approximately 50%.
- Repeat
step 4 as necessary.
TipLock the keyframes as you add them.
Tracking an Erratic Pattern Manually
Using this method, you create part of the tracking
path manually. You can either add a keyframe in each frame, or add
keyframes in significant frames of the clip and extrapolate the
curve for the other frames.
You must delete unwanted keyframes before you
can add new ones.
TipTo go to the desired frame, select Move
in the Edit Mode box and click on the corresponding keyframe in
the image window.
To
track an erratic pattern manually:
- Erase
any bad keyframes by selecting Delete in the Edit Mode box and clicking
the bad keyframes in the image window.
- Go
to the last good frame before the frame where you want to start
tracking manually.
- Click
Snap to redefine the reference on this frame.
NoteIf you are tracking a whole clip manually,
position the reference box on the pattern to track.
- Select
Add from the Edit Mode box.
- Select
one of the following options from the Interpolation Mode box.
- To
set critical keyframes only, select Hermite.
- To
set keyframes on every frame, select Linear.
- Add
a keyframe by holding Shift and dragging
the tracker box over the reference point.
You should see the reference image in transparency.
The keyframe is added in the following frame when you release the
mouse button or lift the pen.
NoteIf you do not see the reference image in
transparency, make sure you have defined a reference and check that
the Opacity is set to approximately 50% in the Setup menu.
- Repeat
step 6 for every frame where you want to define a keyframe.
- Play
the clip and adjust the tracking path by moving or adding keyframes.