Tracking a very low angle

Hi,

I’m trying to remove the patches in the road from this shot. It’s not a very fast moving shot, the picture car is moving slow and the camera car is overtaking it. But the camera does go right over the patches.

I’m having a big problem getting a good track with Mocha. I’ve tried tweaking options and keyframing search area like in the Difficult tracks tutorial, but to no avail.

Is this a case of Mocha not being the right tool, or am I doing it wrong?

I though about 3d tracking it and doing camera projection.

Max

https://drive.google.com/open?id=0BwX70qrZkHt2dDQ0OEh6VzNVZGM

Hi Max,
Have you tried turning link to track to none?.
In situations like this where the area to be tracked is continuously moving but always in shot, I find you often get better results by preventing the tracking area from following the track.
Difficult to see other problems on a still frame but I imagine lens flare and shadows would also cause problems so I’d probably be looking at using multiple splines on one layer that focuses on areas of detail if that is possible.
cheers
gerry

This kind of shot might be better served with offset patches, because roads are notoriously hard to track, it’s a lot of similar looking planar data and can confuse the image recognition.

I tried doing the none linked track and that helped a little, but anything beyond a few frames and it goes nuts.

Unlinking the track won’t fix it, but changing tracking parameters to Translation only will help. You may also need to increase percentage of pixels used, angle, and zoom settings in your track parameters.
Or, if you’re using accelerated tracking, turn that off and restart mocha.

Accelerated tracking?

If you’re using mocha Pro 5 accelerated tracking is an option.