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Camera Tracking

 
 
 

You can perform automatic 3D tracking based on the camera properties of the device used to acquire the image sequence you want to track. You can specify these properties, or let the analyzer automatically detect the best solutions for the analysis. Even if you want to perform object tracking on specific moving areas of the scene, you also start with an analysis using camera tracking to create a properly tracked camera.

NoteTo improve the results of the track, consider adding 2D manual trackers either pre- or post-process (see Obtain better tracking results by adding manual trackers ).

To create a 3D camera track:

  1. Add an Analyzer Mono or Analyzer Stereo node, as explained in Adding an Analyzer Node.
  2. In the Camera Tracking menu, set Analysis options. For example, decide if you need to use a matte or GMask in the analysis. In an image sequence of a busy street, you can create a matte or mask of moving elements (such as cars and people) to isolate this area from the analysis. See Analysis Settings for details of each Lens Correction, Constraints, and Camera setting.
  3. Enable Forward & Backward to track the image sequence backward after the forward tracking has completed. This option takes longer, but you may get better results.
  4. If needed, adjust the size and number of trackers.

    Smaller trackers can speed up the calculation, while larger trackers make the analysis more robust with regard to image noise and variations. A general rule is to increase the size of the trackers when tracking high-resolution footage (2K or larger) that contains more noise.

  5. Click Analyze.

    You can see a progress indicator beside the Analyze button. You can interrupt the analysis and resume it by clicking Analyze again. Most of the time, tracking occurs in the background, allowing you to continue working while tracking. In Batch, you can use connected input and matte clips as the media to be tracked. In this case, tracking becomes a foreground process.

    After tracking has completed and you press Confirm, the Analyze button changes to Update, and you can see the 2D tracks (the blue squares in the following example) and 3D points (green crosses) in your image, provided that you are in Analyzer 3D view.

    Image courtesy of Behavior Communications Inc.

    The FBX camera connected to the analyzer node synchronizes to the results of your 3D tracking, and any further changes you make to the 3D track are reflected in this camera.

  6. If you are satisfied with the results of the tracking analysis, proceed to Converting the Camera Analyzer Results. If you want to tweak your track results, see Fine Tuning the Analysis.
    NoteAs a general rule, a generated Refine field value between 1 and 1.5 is considered a good quality track.

Camera Tracking Settings

Use the settings in the Camera Tracking menu to perform an automatic 3D track.

Camera Tracking button
Displays the Camera Tracking menu, where you can track based on the settings of the camera.
Track button
Tracks the image (when complete, Track button changes to Update).
Analyze Progress field
Displays the progress of analyzing or updating. Non-editable.
Analyze button
Click to delete all previous 3D points, and start tracking based on new information.
Refine button
Click to use the current results of the track analysis as a starting point, and refine from this point. Click Refine again to stop the process.
Pixel Error Value field
Displays a representation of the distance of 2D tracks from repositioned 3D points. Non-editable.
Forward & Backward button
Enable to track the image sequence backward after the forward tracking has completed.
Size field
Displays the size of the trackers. Editable.
Number field
Displays the number of 2D tracks created by the analysis. Editable.
Reset Tracker button
Resets all tracker data in the Analyzer menu.

Changing the tracker display

You can change the display of the tracker icons with the following settings:

Tracker Display button
Enable to display 2D tracks in the image.
Tracker Display colour pot
Displays the colour of the trackers. Editable.
Points Cloud button
Enable to display 3D tracker points in your image.
Points Display colour pot
Displays the colour of the points. Editable.
Transparency field
Displays the transparency level of the trackers and points in the image. Editable.
Point Size field
Displays the size of the 3D points in the image. Editable.
Display Grid button
Enable to display the grid lines in Result or Object view.

You can change the display of the perspective grid with the following settings:

Show Perspective button
Enable to display the grid corners in the Analyzer view.
Show Grid button
Enable to display the perspective grid in the Analyzer view.
Grid Colour pot
Displays the colour of the grid lines. Click to change the colour.
Magnifier button
Enable to display the magnifier while dragging a corner of the perspective grid rectangle in the Analyzer view.
Zoom field
Displays the zoom factor of the magnifier. Editable up to 5x.

Lens Correction Settings

Use the these settings if you want the analysis to take lens correction into account.

Lens Correction Mode box
Select Manual and set the Magnitude and Adjust fields if you want to apply lens correction during analysis.
Magnitude field
Displays the magnitude of lens correction. Editable.
Adjust field
Displays the level of secondary adjustment of lens correction. Editable.

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