Modifying Tracking Data With Expression in Nuke

In this tutorial I build on the custom stabilize and match move nodes that I built with expressions in my previous video to add a control that allows us to adjust the scale of the match move or stabilize effect and allows us to animate the effect over time.

Here are the expressions that I used in the stabilize node:

((Tracker1.tracks.1.track_x(ref_frame) - Tracker1.tracks.1.track_x))*amount
((Tracker1.tracks.1.track_y(ref_frame) - Tracker1.tracks.1.track_y))*amount

And these are the match move expressions:

(Tracker4.tracks.1.track_x - Tracker4.tracks.1.track_x(ref_frame))*amount
(Tracker4.tracks.1.track_y - Tracker4.tracks.1.track_y(ref_frame))*amount

Remember that amount is the name of the slider that I added to the node and represents the scale of the final result. A value of 1 will give you the original result and a value of 0 will mean that the expression will have a result of 0 so will have no effect on the image.

I have saved a simplified version of the two nodes, without the clips, here for you to download yourself. Rather than saving as a .nk file, which some of you might not be able to download at your studio, I’ve saved the script as plain text so you can simply copy and paste this int a Nuke script.