Cloning using motion track.

[Simon Bonner]

If you applied the tracking data to the null, you need to parent the new layer to the null, not the null to the new layer. Layers follow their parents, not vice versa. It’s hard to know if this will solve your problem from what you’ve said, but hopefully it’ll do the trick.

Simon Bonner

youtube.com/simonsaysfx

[Stuart Elith]

You don’t actually need to apply the tracking data to a null (though you can if you want). I prefer not to, as it keeps one less layer in the timeline and I don’t delete my original tracking markers after I use them, so i can just access them in the original footage.

So what I do is this :

1. Track the feature.
2. On the first frame, do your cloning. Make sure the clone settings are set to Constant duration rather than just a single frame. You will need to think about where to choose your clone point so that it will be consistent throughout the shot and won’t reveal the stuff you’re trying to hide (if you don’t get what I mean, it will make sense once you try it! It may work, or may require tweaking, but that’s ok too).

3. Add an expression to the Position of the clone stroke (in the timeline, it will look something like Effects > Paint > Clone 1 > Transform : Clone 1 > Position. You need to pickwhip this to the Motion Tracker track point’s Feature Center.

And that’s all!
If it isn’t perfect, you can adjust the Clone Position of the stroke (in the Stroke Options), which is great as you can then reposition it and see the results… you could even keyframe it if there is just one little bit that goes wrong.

[Gary Noden]

do you know what the script code would be to paint that clone stroke, so I can automate this sort of process with a script?

Thanks