SVO skeleton tracking keypoints values are nan

Software C++
1

Hi there,

I need to make an app that uses the “ZED SDK/samples/object detection/birds eye viewer” as a video player, then I have a GUI with two sliders to set a minimum frame and a maximum frame, a play/pause button and an export button. The app must export metadata values of the keypoints of a person detected for each frame between the min frame and max frame.

This is what I do:

while (
#if ENABLE_GUI
        gl_viewer_available &&
#endif
        !quit && zed.grab(runtime_parameters) == ERROR_CODE::SUCCESS) {
                // if min trackbar changes
                if (trackbar1_changed)
                {
                    zed.setSVOPosition(actual_frame);
                    zed.grab(runtime_parameters);
                    trackbar1_changed = false;
                }
                // if pause button is pressed
               if (!gui_is_play)
               {
                    detection_parameters.enable_tracking = false;
                    returned_state = zed.enableObjectDetection(detection_parameters);
                    zed.setSVOPosition(actual_frame);
                    zed.grab(runtime_parameters);
                    detection_parameters.enable_tracking = true;
                    returned_state = zed.enableObjectDetection(detection_parameters);
              }
...

The thing is that as soon as I set the SVO frame the keypoints (zed.setSVOPosition(actual_frame);) the keypoint values start being nan ([0] = {x=-nan(ind) y=-nan(ind) z=-nan(ind) ...}).

As you can see, I’ve tried both ways:
Without the tracking already enabled:

            zed.setSVOPosition(actual_frame);
            zed.grab(runtime_parameters);

And with the tracking disabled:

            detection_parameters.enable_tracking = false;
            returned_state = zed.enableObjectDetection(detection_parameters);
            zed.setSVOPosition(actual_frame);
            zed.grab(runtime_parameters);
            detection_parameters.enable_tracking = true;
            returned_state = zed.enableObjectDetection(detection_parameters);

And both returned the keypoints nan.

Any ideas on how to do it right?

Thanks!