Additional Nexus reference PDFs:

Nexus legacy documentation:

This information is for Vicon Nexus 2.14. For up-to-date help, see the latest Nexus documentation.

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If you run a CGM2 - Functional Calibration pipeline operation on lower body only data, the operation fails.
Run the CGM2 - Functional Calibration operation on full body data only.
If you use a SACR marker instead of the LPSI and RPSI markers, and you try to run the CGM2 - Functional Calibration pipeline operation, CGM2 doesn’t work with Nexus and CGM2 calibration errors are logged.See Modify the Translators information.
When you run a CGM2 pipeline operation in Nexus and generate a MKR file, the forearms may be poorly scaled. Also, for CGM2.4 and later, the feet may be offset.In Polygon, manually adjust the mesh visualization segment scales.
You installed Nexus 2.9 or later, having previously installed CGM2 standalone (ie, pre-Nexus 2.9) and encounter issues running CGM2.Delete this folder:
You can't find the version number for CGM2.See Find the version number of CGM2.

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 Vicon pyGM2, please contact

Modify the Translators information

If you use a SACR marker instead of the LPSI and RPSI markers and need to run the CGM2 - Functional Calibration pipeline operation, 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\Vicon\Nexus2.#\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.