This information is for Vicon Tracker 4.0. For up-to-date help, see the latest Tracker documentation.

Vicon Tracker 4 banner

In the Processing panel, you can modify settings which affect how Tracker processes object tracking and the type and/or amount of data it makes available for viewing or streaming.

For normal use cases, you're unlikely to need to change the settings in the Processing panel from their default values. For guidance on how to configure the Processing panel for specific applications (ie, high object count or high frame rates), see Understand object booting or contact Vicon Support.

Any setting displayed in bold and italics has been changed from its default value. To return a setting to its default value, at the right of the relevant line in the panel, click the parameter context menu button and select Set to default . To set all values to their defaults, click the Default parameters button at the top right of the Processing panel.

Some properties are available only when advanced properties are displayed (at the top right of the Properties pane, click Advanced Parameters ).

Object Tracking section

Tracker 4 uses two strategies for object identification: booting and tracking:

  • Booting uses the 3D reconstructions along with the object's known dimensions to locate and fit an objects pose.
  • Tracking uses the object's pose information from a previous frame.

In general, if the current frame can't identify an object, the next frame uses booting; if the current frame has the object, the next frame uses tracking.

Low Jitter Mode

Sets all cameras to pass grayscale data, allowing jitter reduction algorithms to work. For large systems this may cause system instability, due to network overload.
Default: Enabled

Thread CountSpecify the number of threads to use. If zero (the default), the thread count is automatically calculated.
Default: 0
Enable Constant Velocity TrackerWhen selected, tracking for fast-moving objects is improved. However, it requires more computation so increases latency and decreases throughput.
Default: Enabled
Reprojection Threshold

This threshold (in pixels) is used when forming correspondences between centroids and model points. If the camera calibration has drifted and correspondences are being missed then this value can be increased. This value is only used when Auto Bias Handling is disabled.
Default: 1.5

Entrance Threshold

The minimum proportion of markers that must be visible to the system before the object is booted. If it is less than this value, the object is not booted. You can override this value for selected objects by using Object Presets (see Create an object preset).
Default: 0.00

It is important to note:

  • Three markers must be visible before booting can occur.
  • The marker proportion always rounds to the next whole number (eg, if you want the entrance threshold to be for 6 of 7 markers, set the Entrance Threshold to 0.86).
Maximum Boot Iteration CountThe maximum number of iterations allowed for the booting algorithm. Increasing this parameter improves booting quality, but has a small performance cost.
Default: 100
Minimum Object Marker SeparationThe minimum distance allowed (in mm) between marker positions in order for them to be tracked separately.
Default: 10
Boot Recon. Min. CamsThe minimum number of camera rays required to generate the reconstructions that are used for object booting.
Default: 2

Camera Healing section

Enable Bias HandlingComputes and corrects for camera calibration bias. See Auto Bias Handling for more details.
Default: Enabled
Enable Auto Recover Camera PoseEnables automatic recovery of bumped cameras. See Auto Recover Camera Pose for more details.
Default: Enabled

Performance Tuning section

Bias Handling State ThrottleProcess every nth frame when computing the camera calibration bias.
Default: 45
Live System Health State ThrottleControl how much processing is required for system health, by considering only every nth frame, eg, for a system frame rate of 100 Hz, set to 100 to process 1 frame every second.
Default: 1

Reconstruction section

Unlabeled Recon. Min. CamsControls how many cameras (rays) must see the same marker (centroid) to create a new reconstruction. The minimum value that can create a reconstruction is two cameras. The maximum value of this parameter is 50 camera rays. If there are a large number of unlikely reconstructions being created, increase this value.
The default value for this property is 3 (ie, three cameras), so if you are using a two-camera system, ensure you change the value to two before starting to work with Tracker.
Default: 3
Environmental Drift Tolerance

An uncertainty applied (in mm) to camera calibration to take into account environmental factors such as temperature change, that may cause drift in the calibration. For larger volumes, increase this value; for smaller volumes, decrease this value.

This setting applies for unlabeled reconstructions and when booting reconstructions.
Default: 1.50

Reconstruction Minimum SeparationThe minimum distance, specified as a value in the range 0–100 mm, allowed between 3D marker positions in order for them to be considered for reconstruction. If two candidate reconstructions are closer than this minimum separation, only the most likely reconstruction (in terms of the number of cameras contributing) will be reported. The other will be discarded. A higher value decreases the likelihood of creating spurious reconstructions, but increases the possibility that some genuine markers will not be reconstructed.
To turn off this feature, set the value to 0.0.

This setting applies for unlabeled reconstructions and when booting reconstructions.
Default: 14.00
Enable Unlabeled ReconstructionsEnables generation of reconstructions using centroids that are not labeled as object markers. Enabling will allow you to create objects, add markers to an existing object, or align an object's orientation to a marker not associated with the object. If low latency is desired, this option should not be checked.
Default: Enabled

Output section

Pause Buffer SizeThe size (in seconds) of the output cache. For more information about the Pause Buffer, see Live Review.
Default: 10.00 s

DataStream Output section

Include Unlabeled ReconstructionsAdd unlabeled reconstructions to the datastream output.
Default: Cleared
Include Object QualityAdd object quality to the datastream output.
Default: Cleared