Group editor is the main control point of the tracking module. It includes the following tabs:
- Calib. report
- Ground calib.
Determines in which mode the group will operate after clicking on Start button . Three modes are available:
|retrieve and display camera info (images and points)
|retrieve and display camera info (images and points) + 3D reconstruction + object tracking
|the mode for camera calibration
- Multiple marker Id (Let All; Most * Left,Right,Top,Bottom; Remove All)
This parameter determines the policy towards the markers detected more than once (mostly due to reflections)
- Enable passive marker (on/off)
If the parameter is off, passive markers are discarded. This parameter is forced to on during calibration.
- (for calibration mode only) from capture button may be used to perform camera calibration using existing wand data, typically from the previous calibration. Calibration data is stored in
- (for calibration mode only) Min wand distance (m) defines the minimal distance between two markers on the calibration wand.
- (for calibration mode only) Total wand distance (m) defines the distance between two farthest markers on the calibration wand.
- Auto set mode
Use the preset of camera settings when starting the tracking in a given mode. When deactivated, all cameras in the group will start with the last used settings.
- Preset buttons: apply a preset to the selected tracking group
- Camera calibration: preset for camera calibration mode.
- Projector calibration: preset for 3D calibration of outputs.
- Tracking: preset for tracking.
- Force parameters
Allows changing settings of all cameras inside the group all at once. For more details about each parameter see Tracking camera editor
This tab reflects the result of camera calibration.
Mean. reproj. error describes the mean reprojection error in pixels. It denotes the distance between the calculated marker position and the true one. The value of mean reprojection error will greatly depend on your setup, however, should not be greater than 1.0px. In fact, the lower the value the better.
Reprojection error summary. This table describes the calibration results for each camera one by one.
- Nb points: number of points actually used for calibration
- Reprojection error (%) < 0.5px: percentage of points with the reprojection error lower than 0.5px
- Reprojection error (%) < 1px: percentage of points with the reprojection error lower than 1px
Wand reconstruction error.
One of the steps of camera calibration consists in 3D reconstruction of wand points and the corresponding table shows the percentage of points with the error lower than 1mm, 5mm, 1cm, 5cm, 10cm.
In addition, the resulting point cloud will be saved in
A calibrated set of cameras (calibrated tracking group) is defined by the fact that the relative disposition between cameras is known, which is not true for the absolute position. In other words, the point with coordinates (0,0,0) in camera frame doesn’t correspond to the world origin or the origin of your 3D Scene. In order to find the lacking transformation, one has to use a groud calibration square.
In a typical setup, the square is placed in the following way: Z-axis points towards “stage right”, Y-axis up, X-axis towards the audience.
Enable ground calibration (on,off). Apply a ground transformation to tracking markers or not.
Gound square type (Official Modulo-Pi, custom) allows choosing the type of calibration square. In custom mode, you chose the fields below (Corner, Smallest distance, Largest distance).
Gound offset (in meters) defines Y position of zero in relation to the XZ plane of the calibration square.
- (for custom type only) Corner : Physical measure defines the true metric position of the corner LED in a new frame. 3D measure button acquires the actual position from the “Position spy” graph block, i.e. position of the corner LED in the current frame.
- (for custom type only) Smallest distance : Physical measure defines the true metric position of the LED closest to corner in new frame. 3D measure button acquires the actual position from the “Position spy” graph block, i.e. position of the LED in the current frame.
- (for custom type only) Largest distance : Physical measure defines the true metric position of the LED farthest from corner in new frame. 3D measure button acquires the actual position from the “Position spy” graph block, i.e. position of the LED in the current frame.
Calibrate button. Finds the transformation between the camera frame and the new world frame defined by the calibration square. This button is active only if: 3D tracking has only three passive markers and Enable ground calibration is off.
Please refer to Tracking objects
This tab is used for listing the reconstructed 3D points in tracking mode.
Remap (on,off) button: defines whether the reconstructed points are displayed in the camera frame or in the world frame.
Listing table has the following format.
|negative for passive markers and positive for active ones
|number of cameras that sees the marker
Please refer to Tracking objects
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