Anchor Mask Paint Stroke Points to Specifics Tracking Points

Hi All,

I'm in the process of designing a line-work graphic for a property video, to outline/border the key features of the home. One of the issues I'm struggling to overcome is manipulating the shape to move with the clip.

As you can see in the screenshot below, I have created an outline around the unique door frame using a mask paint polyline stroke tool:

Screen Shot 2021-07-02 at 4.47.06 PM.jpg (468.55 KiB) Viewed 724 times

Here is a screenshot of the end frame of the clip:

Screen Shot 2021-07-02 at 4.47.20 PM.jpg (446.76 KiB) Viewed 724 times

What I want to happen is for the corners/ends of the mask paint line to move with the point it originally starts in.

I've tried to use a simple tracking node but that doesn't account for the distortion within the clip. I've attempted to make it work with a planar tracker but as it's not a simple plane, more of a 3D shape, this doesn't work well either.

Is there a way to anchor the individual stoke points to separate tracker paths? Or any other way I can achieve the desired outcome?

Thanks in advance

Select the Polygon's anchor points and Shift+P to Publish them. This will provide a separate Point control in the Inspector for each anchor point. These can be linked to Trackers to accomplish what you're after. Just make sure you connect to the offset position of individual trackers within the Tracker node, and not to the Unstable Position of the Tracker as a whole.

Untitled.jpg (157.66 KiB) Viewed 671 times

If you need to tweak the path a little bit, you can animate the X and Y Offset controls in the Tracker. Each individual tracking point has its own offsets.

Untitled2.jpg (107.3 KiB) Viewed 671 times

...and if there is visible lens distortion (for example, the straight lines bend as they approach the edge of frame) you would need to remove the lens distortion, track the lines, then distort them to match before comping them. The basics of this kind of workflow are outlined in simple terms here -

http://www.steakunderwater.com/wesuckle ... 3081ea7fb6

but there are quite a few more detailed online tutorials as to how this works, usually connected to the 3D tracking software used (syntheyes, pftrack etc.)

For lines and smooth motion line curvature can be manually keyframed, could be faster than full undistort-redistort in some cases. And distortion can also be manually approximated using a full frame gridwarp.

[quote="Bryan Ray"]Select the Polygon's anchor points and Shift+P to Publish them. This will provide a separate Point control in the Inspector for each anchor point. These can be linked to Trackers to accomplish what you're after. Just make sure you connect to the offset position of individual trackers within the Tracker node, and not to the Unstable Position of the Tracker as a whole.

This is perfect, thank you very much!