Additional Nexus reference PDFs:

Nexus legacy documentation:

This information is for Vicon Nexus 2.9. For up-to-date help, see the latest Nexus documentation.

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The known issues for CGM2 are as follows:

When you run a CGM2 pipeline operation in Nexus and generate a MKR file, the upper body that is visualized in Polygon's 3D workspace is poorly scaled, so that the head is small and offset, the thorax is enlarged, and the forearms are long.In Polygon, manually adjust the mesh visualization segment scales.
If you use a SACR marker instead of the LPSI and RPSI markers, CGM2 doesn’t work with Nexus 2.9 and CGM2 calibration errors are logged.Modify the Translators information.
You installed Nexus 2.9, having previously installed CGM2 standalone (ie, pre-Nexus 2.9) and encounter issues running CGM2.Delete this folder:

CGM2.2 onwards may fail if gaps at the beginning and end of the trial are present.Ensure the trial does not have any gaps.

Note also that CGM2 is currently only a bilateral model.

For questions regarding CGM2, including the biomechanical model details and known issues, please contact Dr Fabien Leboeuf at:

If you have any questions regarding the Vicon pyGM2, please contact [email protected]

Modify the Translators information

If you use a SACR marker instead of the LPSI and RPSI markers, to enable CGM2 to work with Nexus, you need to modify the information about the relevant markers. This information is stored in the Translators section of the CGM1-pyCGM2.settings file and the CGM1.translators file. To modify the information:

  1. Copy the pyCGM2 folder from:
    C:\Program Files (x86)\Vicon\Nexus2.9\Python\Lib\site-packages\

  2. Depending on how often you use a SACR marker, edit the Translators information:

    • If you use the SACR marker by default:
      1. Edit this file:
      2. Under Translators , change:
        LPSI: None and RPSI: None to
        LPSI: SACR and RPSI: SACR

    • If you use the SACR marker in only some sessions:
      1. Copy this file into the relevant session folder:
      2. Edit the file as described above.