Secondary Colour Grading > Animating the Point Tracker >

# Animating the Shape of Geometries with the Point Tracker

You can use the Track Geom button to animate the shape of a geometry when using Point Tracker. When you animate the shape of a geometry, the vertices of the geometry change position as the moving elements in the shot are tracked.

When you use Track Geom, a Point Tracker is simultaneously assigned to each vertex in the current geometry. You then analyse the shot to generate the tracking data.

To animate the shape of a geometry:

1. If working with a basic shape, right-click it in the Player to convert it to a free-form geometry.
2. In the Secondaries menu, activate the secondary layer button that contains the geometry you want to track.
3. Enable Show.

   The geometries are displayed in the Player.

4. Go to the frame where you want to start tracking.
5. Select the geometry you want to track. In the Player, draw a selection box around the geometry to select all vertices on the shape. Alternatively, click a vertex to select it.
6. Click Track Geom.
   NoteWhen the Diamond Keyer is selected, disable the Show button (beneath the Source Primary button) to display the Tracker panel.

   In the Player, a Point Tracker is assigned to, and positioned over, each vertex on the shape. A tracker number is assigned to each tracker. Gang mode is selected and the Point Trackers are turned on.

   (a) Tracker status(b) Gang mode

   When a Point Tracker is on, it is displayed in the Player and can be analysed. When Gang mode is selected, all Point Trackers assigned to the geometry (and any others included in the gang) will be analysed simultaneously.

   NoteIf other Point Trackers exist, they will be turned off and hidden so as not to be included in the gang. However, if they are assigned to another geometry, their tracking data will still be applied.
7. Use the Analyse buttons to analyse the shot:
   - To track the tracking point forward in time, click the Analyse Forward button.
   - To track the tracking point backward in time, click the Analyse Backward button.

   (a) Analyse Backward buttons(b) Analyse Forward buttons

   The system analyses the shot and generates the tracking data.

8. If the Point Tracker loses the tracking point, click the image to stop the process, and then use the Step Backward or Step Forward button in the Player controls (or press the right Alt or right Ctrl key, respectively) to return to the last frame that was correctly tracked.
9. In the Player, do any of the following:
   - To resize the tracker, modify the Match area (magenta rectangle) and Search area (yellow rectangle) by dragging the vertices of the rectangles.
   - To reposition the Point Tracker, drag the centre point of the tracker.
   - To reposition the Point Tracker and reference point, middle-click and drag the centre point of the tracker.
   TipYou can reposition the Point Tracker and reference point when the reference point moves off-screen.
10. Continue using the Analyse buttons to analyse the shot.
11. To manually add or reposition a tracking point, go to the frame where you want to modify the tracking data, enable Add Key, and then click a tracking point in the image.

    The position of the tracking point is displayed in the image.

12. To manually delete the position of a tracking point, go to the frame where you want to remove the tracking data, and then click Del Key or press Backspace.

    The tracking data is deleted.

    NoteLinear interpolation is used to set the tracking position for frames without tracking data. For these frames, the previous defined tracking position and the next defined position are used to interpolate the tracking position.