"Better" way for edge tracking?

Silhouette
#1

Greetings,

I was able to get an excellent track of a persons profile by drawing a track shape 1: enclosing the edge of the person’s back and a track shape 2: enclosing the edge of the person’s chest. My single roto shape stayed on the edges of the person’s profile very good with minor tweaking.

Contrary to this, when I tried just making a single track shape encompassing the entire body profile, the edges of the single roto shape end up waaaaay off by the end of the 24 frame clip. Visually it does not look like a lot of motion, the person is standing in place with some minor rotation about their y-axis ( vertical axis), so I was very suprised that a single track shape would not have held the edges for the single roto shape.

Is what I did, just using two shapes to track the edges, back edge and chest edge, the “best” way for this type of situation, or is there a “better” technique available for tracking just the edges?

Thanks for any help on this :slight_smile:

Screen Shot 2022-02-05 at 7.30.05 PM
Screen Shot 2022-02-05 at 7.30.05 PM2260×1698 275 KB

#2

That’s expected behavior. When tracking rotoscoping shapes, look for motion groups and track those. Often chests and hips have less secondary animation and are more structured, so they do well with their own shapes, and the stomach has a lot of secondary animation, and does better with it’s own shape. Think paper dolls and points of articulation, and plan your shapes that way.

#3

Thanks for the tips Mary!!