Autodesk 62205-051408-9001 User Guide - Page 721

Deleting Bad Keyframes and Letting the Tracker Interpolate

Page 721 highlights

Advanced Tracking Techniques ❚❘❘ 4. In the Tracker panel, select the source layer from the Source list. 5. Click Position, Scale, or Rotation, depending on the type of motion you want to track. 6. In the Tracker panel, adjust the Tracker settings as required, and then click the Analyze button. 7. When the tracking is complete, turn off the Tracker, and remove or turn off the operator that you added in step 2. Deleting Bad Keyframes and Letting the Tracker Interpolate When the motion is regular between keyframes, you can delete bad keyframes and let the Tracker interpolate the motion between two good keyframes. To delete bad keyframes and let the Tracker interpolate: 1. Pause the analysis when the Tracker loses its reference feature. 2. In the Playback controls, click the Previous Keyframe button . 3. In the Timeline, click the keyframe you want to remove and press DELETE or BACKSPACE. 4. Restart the analysis on this frame (or a later one) until you get a good keyframe. The Tracker interpolates the motion (indicated by a simple straight line, meaning no keyframes) between the previous and next good keyframes. This works best with a few frames, and would not be appropriate for long sequences, as the interpolation is linear. Note: You can also use the time slider to scrub backward or forward through the analysis. Continuing the Analysis with a Different Reference Feature You can continue the analysis with a different reference feature if the one you are tracking moves out of the frame or changes to such a degree it is no longer usable as a reference feature. The Tracker uses the offset between the old and new reference features to calculate the shift values of the old reference feature. That is, it locates the new reference feature and, from its location, determines where the old reference box would be located. It then calculates the shift values for the old reference box and uses these to complete the track. To continue the analysis with a different reference feature: 1. Pause the analysis when the Tracker loses its reference feature. 2. Return to the last good keyframe. This frame must contain both the current reference feature and the intended new one. 3. Select the reference box and drag it to the new reference feature. 4. Restart the analysis. Analyzing Backward Analyze the clip backward when the reference feature grows larger or smaller (change Type to Roaming) or when it is off screen at the beginning of the clip. Note: You cannot analyze backward if you need to change or snap the reference box. To analyze backward: 1. Use the frame controls to go to the last frame of the clip. 2. Position the reference and tracker boxes. 705

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Advanced Tracking Techniques
705
❚❘❘
4.
In the Tracker panel, select the source layer from
the Source list.
5.
Click Position, Scale, or Rotation, depending on
the type of motion you want to track.
6.
In the Tracker panel, adjust the Tracker settings
as required, and then click the Analyze button.
7.
When the tracking is complete, turn off the
Tracker, and remove or turn off the operator that
you added in step 2.
Deleting Bad Keyframes and Letting
the Tracker Interpolate
When the motion is regular between keyframes, you
can delete bad keyframes and let the Tracker
interpolate the motion between two good
keyframes.
To delete bad keyframes and let the Tracker
interpolate:
1.
Pause the analysis when the Tracker loses its
reference feature.
2.
In the Playback controls, click the Previous
Keyframe button
.
3.
In the Timeline, click the keyframe you want to
remove and press
D
ELETE
or
B
ACKSPACE
.
4.
Restart the analysis on this frame (or a later one)
until you get a good keyframe.
The Tracker interpolates the motion (indicated
by a simple straight line, meaning no keyframes)
between the previous and next good keyframes.
This works best with a few frames, and would not
be appropriate for long sequences, as the
interpolation is linear.
Note:
You can also use the time slider to scrub
backward or forward through the analysis.
Continuing the Analysis with a
Different Reference Feature
You can continue the analysis with a different
reference feature if the one you are tracking moves
out of the frame or changes to such a degree it is no
longer usable as a reference feature.
The Tracker uses the offset between the old and new
reference features to calculate the shift values of the
old reference feature.
That is, it locates the new reference feature and, from
its location, determines where the old reference box
would be located. It then calculates the shift values
for the old reference box and uses these to complete
the track.
To continue the analysis with a different reference
feature:
1.
Pause the analysis when the Tracker loses its
reference feature.
2.
Return to the last good keyframe. This frame
must contain both the current reference feature
and the intended new one.
3.
Select the reference box and drag it to the new
reference feature.
4.
Restart the analysis.
Analyzing Backward
Analyze the clip backward when the reference
feature grows larger or smaller (change Type to
Roaming) or when it is off screen at the beginning of
the clip.
Note:
You cannot analyze backward if you need to
change or snap the reference box.
To analyze backward:
1.
Use the frame controls to go to the last frame of
the clip.
2.
Position the reference and tracker boxes.