Additional Nexus reference PDFs:

Nexus legacy documentation:

This information is for Vicon Nexus 2.12. For up-to-date help, see the latest Nexus documentation.

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When you created your custom labeling skeleton template, you captured a static trial (see Capture and reconstruct the marker set). Static trials are easier to work with than movement or ROM trials when using the Nexus skeleton-building workflow (see Create the skeletal structure). However, a static trial does not produce skeleton parameters that are likely to be representative of the movements to be captured in the dynamic trial, so it may not produce the best labeling. To improve labeling, you can provide more representative data by capturing and calibrating a movement or ROM trial. Nexus can then use the data from the movement or ROM trial to update the labeling skeleton template (VST).

To optimize a custom VST:

  1. Capture a ROM trial. To do this:
    1. With Nexus in Live mode, in the Subject Preparation pane , click Start in the Subject Capture section.
      The Start button label changes to Stop.
    2. Have the subject hold the base pose for one second and then move the segments within the VST through as full a joint range as possible. To produce the best calibration and auto-labeling, ensure that each joint is moved through a range that represents the movement that is likely to be captured during movement trials.
    3. Click Stop to finish the capture.
  2. Attach your custom skeleton labeling template (VST) to your subject (see Create a new subject from a template in the Vicon Nexus User Guide).
  3. Reconstruct and label the ROM trial, using the Reconstruct and Label pipeline, and manually label markers as necessary (ie, if markers become unlabeled). Do not perform any gap filling. 
  4. To calibrate the ROM trial, run a Calibrate Labeling Skeleton ROM pipeline. This pipeline optimizes the skeleton parameters used for autolabeling, including joint and marker positions for the whole trial, and calculates joint and marker statistics. If you have any calibration-only markers, before running the pipeline, select Functional Skeleton Calibration from its operations list. Open its Advanced properties and make sure Remove Calibration Markers is cleared.
  5. After you have run this pipeline, you must update the VST to match the data that was calculated for this specific subject (VSK) during the ROM trial. To do this, double-click the Update Skeleton Parameters operation. Before running the operation, in its Advanced properties, ensure that Update Parameters is selected.
  6. To set the pose used for autolabeling the static frame in future trials, choose a frame in which the subject is standing in the desired pose and, also in the Pipeline Tools pane, under Subject Calibration, select and run the Set Autolabel Pose pipeline operation. To check the pose is correct, you can change the view type from 3D Perspective to Subject Viewer.

You can now save the custom VST (see Save a custom labeling skeleton template).