Simple transform track with Adjustments

I’m in Mocha AE. I am trying to do the classic two point track to do a light saber effect. When I do a track on the base point, there is a moving offset between the hand I’m tracking and where I need to place to origin point. Because the beam plugin needs an absolute and not relative position I attempted to solve this by doing a track of the hand, then making a new track that I link to the first rough track and tried to do a manual track to refine, but the position is not sticking frame to frame. Originally I tried just using ‘adjust track’ which worked only if there we not large deviations in position. How do I achieve this?

Well, it really depends on how good the track is. If you can’t get a good track, it’s unlikely adjust track is going to be much help.

I’d really have to see the shot.

Have you tried tracking translation only?

Mary-

Thanks so much for your response. I am essentially trying to do a point track. I know Mocha is a planar tracker so I need to adjust the surface center somehow. The center should be centered on the base of the blade. See attached example.

Yeah, it’s going to follow the overall texture more than the red base of the blade. Because Mocha is not a point tracker (which you know).

You can try tracking with translation, getting your roto shape where you want it over time, and then retracking again with your edited roto shape. Then you can try using adjust track. You might get a little closer that way.

Ok, thank for the input. The solution I ended up with is: do a basic track in Mocha, apply to null, add a child null to that and adjust position over time, then use this expression to link null to beam plugin coordinates:

c = this_comp.layer(“null”);
c.to_comp(c.anchor_point)

That’s basically a one point adjust track but in AE instead of Mocha. Totally a valid workflow.