Passthrough live cams use the Quest 3's full-color outward-facing cameras to render your real room around a WebXR video layer. Instead of dropping you into a 360° stage set, the headset composites the performer into the chair across from your desk, the couch you're already sitting on, or whatever space you point the cameras at. The cam stream itself is the same stereoscopic feed VR rooms always use - the difference is the background is your bedroom, not a virtual studio.

The term most platforms use for this is mixed reality (MR) or AR passthrough cams. Under the hood it's a WebXR `immersive-ar` session with `environmentBlendMode: "alpha-blend"` - the Meta Browser hands the page the camera feed and the page paints the video plane on top. No native app, no sideloading, no developer mode.

Passthrough cam streaming only runs cleanly on a Quest 3 or Quest 3 Pro. The Quest 2's grayscale passthrough is not usable for this format - the original Quest and Quest Pro can't do full-color passthrough at the resolution the format needs.

Before opening a room:

- Update the headset. Settings → System → Software Update. Color passthrough quality has improved noticeably with every release since v68.
▸ Set up a Stationary Boundary. Guardian doesn't draw a wall in AR mode, but the headset still needs a reference floor.
▸ Turn on hand tracking 2.2. Settings → Movement Tracking. Controllers work, but hand tracking is the natural fit for AR - you keep your hands free for whatever you're doing.
▸ Bright, even room lighting. Passthrough cameras are sensor-limited - a dim room produces grainy passthrough that breaks the illusion. Two soft lights at eye level make a bigger difference than any setting change.
▸ Clean the front sensors. A smudged front plate ruins passthrough clarity faster than a smudged lens ruins the screen.

Meta Browser supports WebXR `immersive-ar` out of the box on current builds - there is no longer a flag to flip. If you're on an older firmware:

1. Open Meta Browser inside the headset.
2. Type `chrome://flags` (yes, even on Meta Browser - the Chromium flags surface is still there).
3. Search for WebXR. Enable `WebXR Incubations`, `WebXR AR Module`, and `WebXR Plane Detection`.
4. Restart the browser when prompted.

On current builds (v74+) these flags are on by default. To confirm the browser is reporting AR capability, open the room URL on a desktop browser first - the page will fall back to a flat preview if AR isn't available. Inside the headset, the same page will show a "Enter Mixed Reality" button instead.

Tap Enter Mixed Reality, accept the camera permission prompt, and the room walls dissolve into your real environment with the performer placed in front of you.

The first time you launch a passthrough cam, the video plane spawns about 1.5 meters in front of where you're looking. That's almost always the wrong spot.

Two gestures handle placement:

- Pinch and drag - Pinch the corner of the video plane with thumb and index finger, drag to reposition. The plane stays anchored to world space, so once it's placed it doesn't follow your head.
▸ Two-handed pinch and pull/push - Pinch with both hands, pull apart to scale up, push together to scale down. Most viewers settle around a 2.0–2.5 meter wide plane at conversational distance.

Good placement rules of thumb:
▸ Anchor the plane against a real wall or piece of furniture. A floating rectangle in empty space looks like a TV; a plane that visually sits on your couch reads as a person on your couch.
▸ Match eye-line. Drag the plane's vertical center to your seated eye height, not the room's center. This is the single biggest thing that sells the presence effect.
▸ Leave at least one real object - a coffee table, a lamp - visible between you and the plane. The brain uses real parallax cues to lock the virtual person into the real scene.

Passthrough adds CPU load on top of the WebXR decode. A stream that ran cleanly in full immersive VR can stutter when composited against camera feed. A few settings to adjust:

- Quality tier. Drop from 4K VR to 1080p VR for passthrough sessions. The performer occupies a smaller portion of your field of view than they do in full immersive mode, so the per-pixel detail is less visible anyway.
▸ Refresh rate. Set the headset to 90 Hz, not 120 Hz. Passthrough camera capture and reprojection both cost frames; 90 Hz holds steadier under that load.
▸ Lighting Match. In some platforms there's a "Match Room Lighting" toggle that color-grades the stream toward the warmth of your real room. Turn it on - it's a small change that does a lot for the composited look.
▸ Anchor before tipping. Place the plane and lock it before opening the tip menu. Re-placing mid-show kills the moment, and accidental pinches during chat input are the most common cause.
▸ Plug in. Passthrough drains the battery roughly 30% faster than full VR. A short USB-C cable to a power bank in your pocket gets you through a private without a swap.

Passthrough cam streaming is more personal than VR by design - the performer appears to be in your space, and your reactions are happening in that space. Two things worth knowing:

The platform never sees your room. WebXR passthrough hands the browser a real-time camera feed for compositing on-device; the feed does not leave the headset, and the cam site receives only the same WebRTC stream a flat browser would send (typically none unless you've enabled two-way cam in a private).

Screen recording captures the composite. If you record your view through the Meta Quest's built-in recorder, the recording includes your real room and the performer. That recording stays on the headset unless you upload it. Re-uploading any cam content violates every major platform's terms of service and most performers' explicit consent.

If you share the headset, set up a Guest Mode profile (Settings → Accounts → Add Account). Browser history, cookies, and WebXR cam sessions stay scoped to your profile.

"Enter Mixed Reality" button is missing. The room is loading the `immersive-vr` path instead of `immersive-ar`. Check the URL for a `?mode=ar` or platform-side AR toggle; if the platform doesn't expose one, the room doesn't support passthrough yet.

Passthrough looks blurry/washed out. Low light - the cameras are sensor-limited. Add a desk lamp pointed away from the headset. Also check the front sensor glass for smudges.

Video plane drifts away from where you placed it. Guardian boundary lost tracking - usually because too much of the room changed (curtains, lighting). Redraw the Stationary Boundary.

Plane shows but stream is black. The page's WebXR AR session is up but the video element didn't autoplay. Tap the plane once to trigger playback - many browsers require a user gesture for video in immersive sessions.

Sharp judder on head turn. Drop refresh rate to 72 Hz temporarily and close any other Meta Browser tabs. Passthrough reprojection at 120 Hz on the Quest 3 is right at the edge of what the SoC can hold.