Preparing to Track

3D Compositing with Action > Action: 3D Camera Tracking >

Preparing to Track

A good 3D tracking result is often footage dependant, therefore you may decide to use the auto or manual 3D tracker. In most cases, the auto 3D tracker gives good results. In some instances, such as when the motion is confined to the axes, and there is little or no perspective rotation, the manual tracker may be a better choice.

Here are some things to keep in mind that can improve your 3D track:

The 3D tracker works best when tracking an image sequence that has a moving camera or environment. Objects or actors that are moving in an image sequence can cause bad results. You should mask these objects so that they are ignored in the tracking process. You should also mask any logos or watermarks in your image sequence.
The 3D tracker analysis is based on point-like and corner-like image features. Balls, spheres, lines, and smooth surfaces are not considered.
Crop out any black areas around your image (such as letterbox areas). When cropping, it is very important to keep the optical centre of the image in the centre, that is, the crop should be symmetrical in both dimensions.
To be able to convert the tracking results correctly, the resolution and aspect ratio of the image being analysed must match the resolution and aspect ratio set in the Action Setup menu.
3D tracking analyses each frame extensively and with high resolution clips, the process can be lengthy. Unlike 2D tracking, however, you are not required to analyse full-resolution clips. In many cases, analysing proxies will produce acceptable 3D tracking results, in a fraction of the time that would be required for the full-resolution clips.
If you have information about the camera that shot the scene you want to track, such as the focal length of the lens and the film back size, you can specify these details to help the 3D tracking analysis.