The Local Vicon System node is the top-level node that is displayed for the Nexus host PC when Nexus is in Live mode. It contains sub-nodes for each device connected to your Vicon system:
- Vicon Cameras
- Vicon Connectivity (Vicon Lock+, Vicon MX Giganet)
- Video Cameras
- Devices (including force plates, accelerometers, EMG, Dikablis eye tracker, etc)
The node for the device designated as the synchronization master is highlighted in bold in the System Resources tree. (For more information, see Change the synchronization master in the Vicon Nexus User Guide.)
For more information on the Local Vicon System node, see:
Local Vicon System node context menu
You can select from the following commands on the context menu displayed when you right-click on the Local Vicon System node:
Reboot Vicon Hardware
Resets all of the Vicon hardware devices in the Vicon system.
Use this command if a camera has failed to boot, or if you need to reset the whole system for other reasons.
Alternatively, use the Reboot All button in the System section of the Properties pane.
Reboot Core Processor
Restarts the Core Processor and resets the labeler. Alternatively, press CTRL + R.
Forces the synchronization master to resynchronize the frame rate for all connected cameras and third-party devices.
Reprogram Vicon Firmware
Display the Reprogram Firmware dialog box in which you can view and update firmware for Vicon devices in your Vicon system.
Local Vicon System properties
You can configure the following settings in the Properties pane for the Local Vicon System node.
If you can't see some of the listed properties, click Show Advanced at the top of the Properties pane.
These settings affect the local Vicon system in Live mode. The equivalent settings for offline processing can be found under Core Processing operations on the Pipeline tab.
Local Vicon System properties are divided into the following sections:
Contains system-wide parameters that affect all the connected cameras and devices.
Requested Frame Rate (Hz)
The rate (in Hertz) at which to synchronize the Vicon cameras. If using external video signal, select from displayed values (multiples of the base frame rate of the PAL, NTSC, or Film video standard specified in Standard) up to a maximum of 2,000. You can choose any number you want if you do not have any Genlock Standard set.
Actual Frame Rate (Hz)
The frame rate used by the Vicon system, which is constrained by the camera frame rate limits.
A list from which you can choose the synchronization master. If you are using multiple devices such as Vicon Lock+ or MX Giganets, to connect and control your cameras, a synchronization master is automatically chosen by Vicon Nexus. If the automatically selected synchronization master is not the required choice, you can select the appropriate device from the Preferred Master list. (For more information, see Change the synchronization master in the Vicon Nexus User Guide).
Buffer Size (MB)
The size (in MB) of the memory buffer on the host PC when Nexus is receiving data from Vicon hardware. Specify a value between 0-1024 MB. This buffer is used if data comes in faster than Nexus can process it; therefore, the larger the buffer, the longer it takes before capture fails. Increasing this value enables a greater Capture Before Start duration to be set. The optimum size of the Buffer Size parameter depends on the amount of memory on your PC. The proportion of the total memory buffer that is reserved for Vicon devices is determined by the Buffer Reserve (see below).
The proportion of the total buffer size (see Buffer Size above) that is reserved for Vicon video devices. The default of 0.5 results in half of the total buffer size being reserved for Vicon video devices (Vicon Vue and Bonita Video cameras). The remaining buffer space is used by third-party video cameras. If you want to maximize the buffer space reserved for Vue or Bonita Video cameras, set this value to 1.0. If you are using only Basler cameras or third-party DV cameras, set this value to 0.
Resets all of the Vicon hardware devices in the Vicon system. Use this button if a camera has failed to boot, or if you need to reset the whole system for other reasons.
Minimizes the level of latency, or lag time, the RealTime Engine introduces during data streaming when data rates approach or exceed system processing capacity.
Genlock and Timecode section
Settings for genlock and timecode.
The type of video standard supported by the connected video source: None, PAL, NTSC, Film (24 fps), Film (24/1.001 fps, 30Hz, VESA (100Hz) or VESA (120Hz). For information about the symbols in this list, see Icons in Genlock and Timecode lists.
Enables genlock based on the signals that are currently detected.
Automatically selects a genlock standard and enables genlock based on the signals that are currently detected.
|Genlock Offset||Enables you to specify a system offset relative to the genlock signal, as a fraction of the genlock frame period. Values are in the range 0–1. For VESA modes, specify a value using the VESA Offset control.|
Applies only if you have selected one of the VESA standards from the Genlock Standard list (see above). It enables a system offset relative to VESA signal (as a fraction of the VESA frame period). It changes when the Vicon cameras take a frame (and hence when the camera strobes are on) relative to the incoming VESA frames. The camera timing can be offset by up to one VESA frame. The main purpose of this feature is to prevent camera strobes from interfering with the IR-synchronized 3D glasses used in some virtual reality systems.
The genlock timecode source. Can be VITC, LTC, Internal or Internal Drop (uses drop frame when applicable). Default is Internal.
When selected, timecode is enabled.
Given as the number of timecode frames per second for example, 24 fps, 25 fps, 30 fps, 30 fps DropFrame
Icons in Genlock and Timecode lists
The icon to the left of each option provides additional information about the availability of that standard:
The standard is not supported by the hardware (that is, no connected device supports locking to a signal of that type). If you select an unsupported standard, it restricts the available frame rates as it does in the previous version of Nexus.
No device in the system is detecting that standard.
Blue square wave
The master device is detecting that signal and can genlock to it.
Green square wave
If you select a mode with the blue wave icon and then select the Enable Genlock check box, the icon turns green.
Red square wave
A device in the system is detecting the mode but a problem prevents it from being used, for example, if the signal is being detected by a device that is not the master device in the system.
In all cases, you can display a tooltip by holding the mouse over the Genlock Standard list.
Settings for the Core Processor component, which receives data from the Vicon cameras and transforms the data to the trajectories or segments that your Vicon system is tracking.
Processing Output Level
The amount of real-time processing the Core Processor is to perform on source data:
Grayscale Circle Fitting section
Select this check box to enable circle fitting of grayscale blobs. If selected, processing speed may be slightly slowed, but more data may be collected.
Controlling the number of cameras that are required to start or continue a trajectory can be beneficial in producing higher quality data. The ability to define how trajectories are created can help you to produce higher quality data that requires less manual editing.
Environmental Drift Tolerance
Increase this parameter to reduce the sensitivity (in mm) of the camera calibration to environmental factors, particularly temperature change.
Minimum Cameras to Start Trajectory
This parameter controls how many cameras (rays) must see the same marker (centroid) in order to create a new reconstruction and potentially form a new trajectory. The minimum value that can possibly create a reconstruction is two cameras. The maximum value of this parameter is 30 cameras or the total number of cameras in your system. This value can be increased if there are a large number of unlikely reconstructions being created.
Minimum Cameras to Continue Trajectory
This parameter controls how many cameras (rays) must see the same marker (centroid) in order to create a reconstruction to continue a recognized trajectory. The minimum value that can possibly create reconstructions is two cameras. The maximum value of this parameter is 30 cameras or the total number of cameras in your system. The value can be decreased if there are gaps in trajectories where reconstruction should be possible when viewed by fewer cameras.
Reconstruction Minimum Separation
The minimum distance, specified as a value in the range 0–1000000 millimeters, 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.
Minimum Centroid Radius
The minimum radius (in pixels) of a 2D centroid that is allowed for a reconstruction. Any reconstruction with a radius less than this value is ignored.
Maximum Centroid Radius
The maximum radius (in pixels) of a 2D centroid that is allowed for a reconstruction. Any reconstruction with a radius greater than this value is ignored.
Minimum Reconstruction Radius
The minimum 3D radius (in mm) that is allowed for a reconstruction. Any reconstruction with a radius less than this value is discarded.
Maximum Reconstruction Radius
The maximum 3D radius (in mm) that is allowed for a reconstruction. Any reconstruction with a radius greater than this value is discarded.
Volume min X
X value of lower corner of reconstruction volume.
Volume min Y
Y value of lower corner of reconstruction volume.
Volume min Z
Z value of lower corner of reconstruction volume.
Volume max X
X value of upper corner of reconstruction volume.
Volume max Y
Y value of upper corner of reconstruction volume.
Volume max Z
Z value of upper corner of reconstruction volume.
Use Target Volume
Sets the reconstruction volume to the dimensions of the target volume (Set the target volume dimensions in the Options dialog box (press F7)
Trajectory Tracking section
Trajectory Startup Error
The deviation allowed (in mm/sec) in a marker's position at the start of a trajectory. This value is related to the radius within which the current trajectory is matched to a reconstruction in the following frame. To help start trajectories on faster moving markers, increase the value. To help with dense marker sets, decrease the value.
Trajectory Prediction Error
The deviation allowed (in mm/sec) in a marker's position on a trajectory. This value is related to the radius within which the current trajectory is matched to a reconstruction in the following frame. To help continue trajectories on faster moving markers, increase the value. To help with dense marker sets, decrease the value.
Label Completeness Entrance Threshold
Specifies the proportion of markers that have to be present when a subject enters the capture volume or when the trial starts. If it is less than this value, the subject is not labeled. Higher values help to prevent mis-labeling when the subject first enters the volume.
Label Completeness Exit Threshold
Specifies the proportion of a subject's markers below which the subject is considered by Nexus to have left the capture volume. Labeling will not recommence unless the proportion reaches the Entrance Threshold. Higher values help to prevent mis-labeling when the subject leaves the volume.
Affects when the system will start labeling based on how well the labeling skeleton matches the reconstructed data. For greater tolerance, reduce this value; to reduce the risk of mis-labeling, increase this value.
Booting versus tracking
Booting is a process in which Nexus attempts to work out the labeling for the active subjects with marker statistics calculated from the VSK. This is done without requiring any information from earlier frames, such as previous labels.
Compares the match between reconstructions and skeleton data with the previous frame to determine whether labeling continues. Adjusting this parameter affects how close this match must be.
Specifies how much the subject markers can move between frames before labeling stops. This value can be increased for slow-moving subjects and decreased for faster motion (at the cost of a greater likelihood of mis-labels).
Joint Ranges Slack
A calibrated skeleton contains joint range information. This informs the labeler about the expected Range of Motion for any joint and the markers associated with that joint, helping the labeler make decisions.
Enforce Joint Ranges
If selected, Nexus considers only a marker labeling solution that adheres strictly to the joint range values defined in the labeling skeleton (VSK).