Tracking 3D camera movement
3D Camera Tracker Fails To Solve Camera (http://www.surfacedstudio.com/)
One of the most common problems that people encounter is that the 3D Camera Tracker ‘just does not work’. You import a piece of footage, throw the 3D Camera Tracker onto the clip and then you get the following error message:
There are 2 likely reasons for why that is happening!
The Camera Movement is too fast
Have a look at the following image sequence, taken from my After Effects building destruction tutorial.
During the explosion, the cameraman dives for cover behind the concrete barrier and the camera’s movement is all over the place. Notice that the individual frames of the footage are extremely blurry and there are no features, no distinguishable shapes for the tracker to lock on to. Even if an accidental feature was found, the camera’s movement is so fast that the feature jumps around the screen, making it impossible for the 3D Camera Tracker to follow its movement.
If your footage includes very fast camera movement with blurry frames and undefined shapes, the 3D Camera Tracker will simply not be able to follow the movement of any features and therefore fail to analyse your footage. If it manages to analyse the footage and produce a cloud of 2D track points it might still fail to solve the camera if there are not enough 2D track points to infer the 3D camera movement from.
In this situation your only option is to re-shoot the scene or work around it. I ended up tracking the first half and the second half of my building destruction video separately because I could not track the middle part where the camera’s movement was too fast.
Moving Foreground Elements
Even if you footage is nice and crisp and there is no fast camera movement, elements in the foreground can interfere with its operation.
You will get the best results when you have no moving objects at all in your scene. That way the 3D Camera Tracker will not track the movement of any moving objects in your scene thinking that they are fixed features. If you have a scene with a large moving foreground element, it can easily invalidate your tracking data. Here is a screenshot of my fireworks tutorial:
The 3D Camera Tracker will pick up my movement and think it’s tracking the movement of a static element in your scene, a feature. To avoid this happening, you have to first mask out any large moving foreground elements to remove them from your footage.
Then pre-compose the layer including the masks and apply the 3D Camera Tracker to the resulting layer.
This way you are giving the tracker only the static geometry of your scene to track and it is much more likely to give you a good track.
But alas, even if all goes well with the tracking, there are yet more problems that you might encounter!