Once all the cameras has been calibrated and their relative position between each other has been reconstructed, the next step is to offset / translate the entire group of cameras so the tracking volume is aligned with the 3D space within SP. There are several options to do this. Depending on how the type of markers and how the markers are arranged, you can choose the appropriate tool.

  • Rigid Body – using a defined Rigid Body as the object to align the Optitrack Volume. Markers need to be placed at the same location as all the points in the rigid body
  • Triangle – using 3 markers to form a triangle with one at the origin point, one on the x axis and one one the z axis. The distance on the x and z axis can be adjusted along with the height offset from the ground plane.
  • Point Refrence – using a number of reference points in 3D space to align the Optitrack volume. Placing markers at the precise location as the reference points in SP to align the Optitrack volume. It is recommended to use at least 4 points.

Similar to the calibration process, once the appropriate alignment process has been defined, and markers are placed at the correct location, press the “+” button next to the recorder section to open up a window to start the capturing process.
Press the “record” button to start the capturing process. This should happen very quickly to capture 1 valid frame from multiple cameras for the alignment process. Once it has been captured, the recording would stop automatically.
Once the capturing of the data is finished, the recorder window can be closed. To run the alignment based on the recording, press the “play” button at the header of the align tool. Once this is completed, the entire group of optitrack cameras would be translated to their location based on the origin point set by the alignment process. This can be double checked in the viewport.