Manual identification of trajectories

Even if you plan on using an AIM model to identify the trajectories, you need to identify at least one file by hand, since an identified file is needed to create an AIM model. Manual identification can be performed with any of the following three methods, and they can also be used together.

Quick identification method

Manual identification is best done with the quick identification method. Follow these steps to use this method:

  1. To use the quick identification method you need to have a label list in the Labeled trajectories window. Load a label list or enter the labels manually with Add new label on the Trajectory info window menu.

  2. Select the first label in the Labeled trajectories window that you want to identify.

  3. Hold down Ctrl + Alt or select the Quick identification cursor and click on the marker or trace in the 3D view window that matches the selected label.

    • When you click on the marker or trace, it will be added to the selected label. If you have not selected any label, the marker you click on will be added to the first empty label in the list. If there is no empty label in the list, the marker you click on will be added as a new label at the end of the list, and you can edit its name at once.

    • You can also add additional parts to a trajectory with the quick identification method. Select the labeled trajectory in the list, then hold down Ctrl + Alt and click on the unidentified marker.
      However, if the two trajectories cannot be joined (because of too much overlap) the selection will just move to the next label without any action.

    • By holding down Shift when clicking on the trajectory you can join a trajectory to the previous label in the Labeled trajectories window. This option can for example be used if the most recently identified trajectory only covers a part of the measurement range. In this case, you can add more parts by clicking on the next part while holding down Shift.

  4. QTM will move the selection automatically to the next label in the list. Hold down Ctrl + Alt every time you click on the next corresponding marker. Continue until all markers in the Labeled trajectories window are identified.

  5. You can start and restart the process on any label in the list.

    • This means that if you click on the wrong marker, you can undo the identification with Ctrl + Z and then make sure that the correct label is selected and use quick identification again.

Drag and drop method

Manual identification can also be performed by dragging and dropping trajectories. The following drag and drop methods are available to identify trajectories:

  • From the Unidentified trajectories window to the Labeled trajectories window.

  • From the 3D view window to the Labeled trajectories window.

  • One trajectory (trace) in the 3D view window to another trajectory (trace) in the 3D view window.

A trajectory can be dropped either on a label to add the data to that label or in the empty part of the Labeled trajectories window to create a new label. If it is dropped on a label that already contains data, the two parts will be joined if they do not overlap.

Identify method

It is also possible to use the Identify option on the Trajectory info window menu, which appears whenever you right-click a trajectory, either in a 3D view window or in a Trajectory info window. For information about functions in the Trajectory info windows, see chapter Trajectory info window menu.

The following features are useful when identifying trajectories.

  • The keyboard shortcut C can be used to center on the selected marker in a 3D view window.
  • The Trajectory info window menu option Center trajectory in 3D, will also center on the selected trajectory or part. However, if the trajectory is not visible at current frame it will also move the current frame to the first frame of the trajectory.
  • The keyboard shortcuts J and Shift + J can be used to jump to the next unidentified trajectory or part.