HOW TO: VPX Mixed Reality Tables Over WIRED USB — No Virtual Desktop Required!

[Spacegoogie]

The Problem:

You're running VPX Mixed Reality tables on Quest 3. Virtual Desktop makes it work — the chroma key passthrough is chef's kiss. Your real room shows through where the VR room sphere color was.

But if you've got Wi-Fi interference (and who doesn't), wireless MR is basically unplayable. Dropped frames, stuttering, passthrough lag. You know.

Wired would fix all of it. But nobody had a documented wired MR solution for VPX.

Until now!

 

The Solution:

ALVR is a free, open-source PCVR streaming tool. You probably know it as a wireless Virtual Desktop alternative. But v20.12 added something nobody talks about:

#1.Wired USB support

#2. Built-in chroma key passthrough

 

After you install: Plug your Quest 3 in, Go thru all the tabs. Make sure to enable Wireless,  enable chroma key in ALVR (RGB Chroma Key, set RGB to 255 ((most tables))) , launch VPX. Done. MR tables work fully wired.

 

What You Actually Need:

Quest 3 (you need color passthrough)

USB cable (Link cable or good USB 3)

ALVR (free, latest release)

Developer Mode on your headset

 

The Setup (5 minutes)

Step 1: Meta Quest Link Settings

Open Meta Quest Link app on PC

Settings → Developer

Turn ON:

Developer Runtime Features

Passthrough over Meta Horizon Link

Passthrough Camera API permissions

Restart the app

 

Step 2: Install ALVR

Download latest from ALVR GitHub (https://github.com/alvr-org/ALVR/releases/tag/v20.14.1)

Install server on PC

Sideload client to Quest 3 (ALVR launcher handles this)

 

Step 3: Enable Wired Mode

ALVR dashboard → Devices

Toggle "Wired Connection"

Plug in headset via USB

Accept USB debugging prompt on headset

 

Step 4: Enable Chroma Key

ALVR dashboard → Passthrough

Enable chroma key mode

Set key color to match your table's sphere (usually green - 0, 177, 64 or white- 255)

 

Step 5: Launch VPX

Fire up your MR table

Real room shows through the keyed color

No Wi-Fi, no interference!

 

Cheers!