Vive Facial Tracker#

This article shows how to set up a Vive Facial Tracker and get it working in VRChat on Linux.

Who this article is for#

• Hardware: Vive Facial Tracker (the square one, not the Focus 3 one).
• Software: Baballonia, VRCFaceTracking (avalonia beta branch), VRChat.
• You don’t mind getting binaries from Steam, instead of building from source.
• You are playing VRChat specifically (this doesn’t cover Resonite yet).

Steps#

Set up Baballonia#

1. Install Baballonia from Steam.
2. Connect the Vive Facial Tracker via USB-C.
3. Launch Baballonia.
4. Click the dropdown labeled Face Camera Address.
   • If you get the warning about “Unable to probe UVC devices”…
     1. Go back to Steam.
     2. Right-click Baballonia → Properties
     3. Set the compatibility tool to one of the following, whatever you have available:
        • Legacy Steam Runtime
          • This option is known to work the best.
        • Steam-Play-None
          • Steam-Play-None must be installed first. Follow the README for instructions. Restart Steam if necessary.
        • Steam Linux Runtime 1.0 (scout)
          • This is what the warning popup recommends, but it didn’t resolve the probe UVC warning for me.
          • If you don’t see this in the list, install it by typing “scout” in the search bar in your Steam library, then restart Steam.
          • Heck, just restart Steam anyway. It tends to hide itself when you move it to a different drive, too.
     4. Restart Baballonia, and restart the steps from the beginning.
5. Look for the “HTC_Multimedia_Camera” and, in the parenthesis, note the number after “video”.
   
6. Manually type in the device file path of the HTC_Multimedia_Camera, based on what’s in the parenthesis.
   • e.g. if it says (video2), type in /dev/video2.
7. In the Preferred Backend dropdown that appears, set it to VFTCapture.
8. Click Start Camera. You should be able to see a live feed appear below the button.

Set up VRCFaceTracking#

1. Install VRCFaceTracking from Steam.
2. Right-click VRCFaceTracking → Properties.
3. In Game Versions & Betas, select the avalonia branch.
   • At the time of writing, “Last Updated” was Jun 22, 2026.
   • You do not need a compatibility tool for this branch, it is native Linux. Leave the compatibility tool option unchecked.
4. Launch VRCFaceTracking.
5. Open the Module Registry in the sidebar.
6. Find the VRCFT-Babble module, and click Install. Nothing may appear to happen, but the Output logs will say “Installed module”…
7. Restart VRCFaceTracking.
8. Project Babble Module should have automatically started itself as the active module.

Using Baballonia and VRCFaceTracking together#

1. Just to be safe, shut down Baballonia and VRCFaceTracking if they are running. The stack has historically only worked with this specific launch order.
2. Launch VRChat first.
3. Ensure VRChat OSC is enabled in the main menu → Avatars → OSC.
4. Launch VRCFaceTracking.
   • It should detect your avatar name and ID. The OSC Connection may say 0 msgs/s in/out, this is okay.
   • VRChat should pop up a notification saying VRCFT has connected via OSC.
5. Launch Baballonia last!
   • This bears repeating: Baballonia must open after VRCFaceTracking for this to work.
   • It should show the live camera feed as ususal.
   • VRCFaceTracking should now be sending a few hundred msgs/s out.
6. Face tracking should be working now!

Images#

Baballonia fully set up, showing a live feed:

Troubleshooting#

Unable to probe UVC devices#

If you get the following popup “Unable to probe UVC devices”, you must set the compatilibility tool as described above in #Steps.

VRCFaceTracking connects to VRChat OSC, but face doesn’t track#

If VRCFaceTracking is started after Baballonia, it won’t work. It will detect your avatar and connect with OSC, but it will be stuck on 0 msgs/s in/out.

The solution: restart Baballonia once. Generally, Baballonia must be started after VRCFaceTracking.

Clicking Stop Camera in Baballonia will crash it#

This is a known issue. You just have to start Baballonia again.