2D tracking of data

With the 2D tracker you can track the 2D data of one camera and present the markers as trajectories in the 3D view window. Because just one camera is used to track the trajectories, they will all be in a plane in front of the camera. This means that you can only measure the distances in two dimensions.

As the 2D data is tracked only in a plane no calibration is used to track the data. The only settings that are needed is the distance between the plane and the camera. That setting and other 2D tracking settings are set on the 2D tracking page in the Project options dialog, see chapter 2D tracking.

2D tracking can be applied either after a measurement as a processing step or by reprocessing a file, see chapter Reprocessing a file. To use 2D tracking after a measurement you have to activate it on the Processing page in the Project options dialog. And then check the settings on the 2D tracking page.

Using 2D tracking

When capturing data which will be used by the 2D tracker it is important that the movement only takes place in a plane and that the cameras are placed so that the camera sensor is parallel with the plane of the movement. Otherwise the distances in the measured by QTM will not be correct. After you have placed the cameras follow these steps to use 2D tracking.

1. Before you start the capture you should activate 2D tracking with Track the measurement and 2D on the Processing page in the Project options dialog. Then, set the settings on the 2D tracking page, see chapter 2D tracking.
   1. Choose which camera to use. 2D tracking can only be applied to one camera at a time. So if you have more than one camera in the camera system you must retrack the file to get the trajectories for another camera.
   2. It is a good idea to use filter so that you do not get may short trajectories.
   3. Measure the distance between the measurement plane and the camera sensor and enter the Distance to measurement plane setting.
   4. Define the orientation of the coordinate system with the three settings for the axes.
2. Start a capture with Start capture on the Capture menu. 2D tracking cannot be applied in real-time so you have to make a measurement to see whether your settings are correct.
3. When the 2D tracker is finished the result is trajectories that can be processed and handled exactly as trajectories created by 3D tracking. The only difference is that the trajectories will all be in the same plane.