[SOLVED] Some tracking advice please

Hi all, I've just upgraded from Express to Pro and I am having a real hard time achieving the result I want with a particular comp so I thought I'd ask for some advice.

Using this video, I am trying to track the top of the truck as it moves along, so that I can overlay another comp of a circular sign above it. The aim is to make it appear that the sign is floating above the top of the truck cab as it moves along the road, like this (screenshot).

At first I thought Foundry Cameratracker would track the truck as a 3D object allowing me to "pin" the sign to it, however I've found that it only tracks the ground plane and the camera's progression along it.

Then I tried Mocha, adding a spline to the top and side of the truck, but Mocha couldn't seem to track either plane all the way, potentially due to contrast issues.

I then tried a two-point track on the front-facing corners of the top of the truck, this gave fairly good results except for at the end as once the truck has gone off screen I've had to guess where they go and don't seem to be able to get it quite smooth enough to look real. 

Hoping for some advice from the community.



  •  Maybe try tracking the tail end of the truck instead?

  •  I did try that, but then the sign appears to be floating over the end of the truck... if I try to offset the position of the sign in relation to the tracking points it just doesn't look right

  • @stevelawrencenz

    "Fairly good results" Don't be so picky, your results are very good and only a picky creator would see anything wrong. :-)

    You could keyframe the sign to fade out right at the end and don't worry about where to end.

    Or you could look at this tutorial from Production Crate


    Hope this helps, you are talented.

  • Two-point tracking is what I would use. You can use the Alt-drag offset to move the features being tracked once the cab goes offscreen, without moving the position of the tracking. that function is specifically for situations like this where the feature being tracked goes offscreen or is otherwise obscured. From the manual:

    Repositioning the Feature Area

    During tracking, if the feature you are tracking leaves the frame or becomes untrackable for some other reason, you can reposition the Feature Area without moving the Feature Offset. If this becomes necessary, hold ALT (OPT on Mac), and drag the Feature Area to a new feature that is in frame, or better suited to tracking.


  • Thanks so much for all of your suggestion, and the kind words. I wasn't aware of the re-positioning feature that Axel mentioned, and was able to get a good result from it. Love learning this stuff!

    Thanks again!

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