3D Comera Tracking

The most important part of the Camera Tracking workflow is to set an origin and ground plane on a flat piece of horizontal geometry in the scene, then add a solid to the same point, add Effects>Generate>Grid and then check the grid and make sure you have:

1. Picked the right markers for the surface you want to use for the origin and ground plane
2. Have a good camera track

If the Grid does not stick to the ground then you either picked the wrong markers or your track is no good. I recognize that shot and it is a difficult one to track because there is very little geometry in the shot that is flat. The origin and ground plane is important to establish so you can arrange things in the scene and make them stick to the geometry in the shot.

Once you get a good origin and ground plane it is a fairly easy thing to attach placeholders or text to other elements in the shot. If you are having problems attaching placeholders or Text to the scene you can sometimes fix the problem by simply opening up multiple camera views and making some small adjustments.  Other times you must delete the placeholder and try and find at least 3 tracking points that line up with a flat surface. Sometimes it is helpful to slowly scrub through the shot and look at the tracking markers, then pick ones that stick around for several frames and seem to be attached to a common surface.

Anything that is moving in the shot can foul up a camera solution. For example, you cannot Camera Track a shot of the ocean or a crowded city sidewalk that is completely full of people because there are not enough surfaces in the shot that are not moving.

I hope this helps. AE's camera tracker works very well if you have the right kind of shot and there is very little lens distortion in the shot. Lens distortion can be fixed, sometimes you can eliminate the trackers that have attached themselves to things, like people, that are moving through the shot. No camera tracking software can successfully track every shot. They all have their limitations.