World Coordinate Normalization

World Coordinate Normalization

If, after calibration you find that OpenPTrack's world coordinates do not match what is needed for your visualization or interactive system, the coordinate system can be changed manually. We have found that using three reference points works best, with one of the points being 0,0. To change the coordinates:

First, launch roslaunch detection detection_node_<sensor_id>.launch for each sensor in your system. Once all the sensors in your network are detecting run:

roslaunch opt_calibration opt_define_reference_frame.launch

Now, a GUI will open showing the video feed from one of the sensors. You can right click to cycle through all the sensor's video feeds. Once you have the sensor's video feed up that you would like to set a new coordinate from, click on the spot in the video that will be a reference for the new coordinate system. E.g. if you are going to set the new 0,0 for the coordinate system, and that 0,0 us visible in the video feed, left click the spot.

Now in the terminal window that roslaunch opt_calibration opt_define_reference_frame.launch was executed in there will be prompts asking for the X and Y coordinates, then them into the prompt.

Repeat this process until you have entered in all the coordinates to re-orient OpenPTrack's world space. Use the middle click on your mouse to save the new world coordinate system.

3.        right click to see next imager
   

4.        left you select a point in the image to set the coordinate
   

5.        The terminal window will walk you through the rest of the process
   

6.        Distribute the calibration file as normal