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Using Boris Continuum Complete with Apple® Motion®

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Adjusting Tracking without Keyframes

You can also adjust tracking without using keyframes. However you should be careful working this way because if you

make a mistake your effect could jump.

Move the playhead to the point where BCC lost tracking, adjust the Tracker Center KF, and continue tracking. Notice

that the tracked frame markers turn from green to magenta. This indicates that the Tracker Center KF is different from

the current value.

This method works unless you move the playhead to an earlier frame with the Track on the Fly checkbox selected. If

you go back, the tracker retracks that frame using the new (incorrect for that frame) value of Tracker Center KF, and the

Þnal render will jump. Since you haven't saved the Tracker Center KF value for the start of the effect, you have to re-

enter a value and retrack.

If you use this method, we recommend closing the Motion Tracker group as soon as you Þnish tracking, so you

don't inadvertently change the tracker data.

Adjusting Tracking with Hold Keyframes

We recommend that you set keyframes to Hold interpolation for most adjustments. At the frame where the effect loses

tracking, create a new Hold keyframe and set the

Tracker Center KF

the location of the object. Then continue tracking.

If the object goes behind another object for several frames, you can create a Hold keyframe at each frame where the

object is obscured.

You can also put a Linear keyframe where an object becomes obscured and a Hold keyframe where the object becomes

visible again. The tracker will use the interpolated values as the location of the tracked object while it is invisible. You

can add new keyframes in your timeline as needed to adjust the motion while the object is concealed.

Trimming Motion Tracked Effects

When you trim or slide a clip that has been motion tracked, the Þlters do not purge the tracked data. This means that if

a clip is trimmed from the end, you do not need to do anything. If a clip is trimmed from the beginning (or if you slide

the clip, which is the equivalent of trimming from the beginning and end), you should press the

Reset button

invalidate all of the motion tracker data and retrack your effect.

Motion users must change or toggle a control in the effect after clicking the Reset button to purge the cache.

Tracking Part of an Effect

At times you may want the track an object for only part of the effect. To track the object to a certain point and then hold

at that point, simply stop the tracking when it reaches that point. The rendered effect will follow the object for as long

as it has tracked, and then hold.

If you want the effect to hold for a while, then start tracking the object at a particular frame, follow the steps below.

Move the current-time indicator to the frame where you want to start tracking and add a Linear

Tracker Center KF

keyframe.

Create a Linear keyframe at the beginning of the effect, setting its value to a fraction of a pixel different from the

value in step 1.

Track your effect. The tracker will assume that there are keyframes at every frame up to the one you set in step 1,

so it won't track at that point in the effect. Once it reaches the second keyframe, it will track normally.

Tips for Setting Up the Target Area

• A good Target area contains a high-contrast object with good vertical and horizontal edge deÞnition. Ideally, you

should Þnd a pattern that is visible in every frame.

• The Target Width should be large enough to accommodate a good target image. However, processing time

increases as the size increases, so do not make the Target Width unnecessarily large.

• If your image does not contain a high-contrast object and you have trouble tracking, apply the BCC Unsharp Mask

or BCC Brightness Contrast Þlter to the Source track to increase the contrast for better results.

• Tracking is more accurate when you preview in Full Quality rather than Draft Mode.

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