Pico Passthrough Camera White Balance

[UbootVRC]

Description

On Pico 4 Enterprise (OS 5.13.7.S), the passthrough feed rendered during an ALVR session has a
strong white balance / exposure boost applied — the image looks washed out and
noticeably brighter than the headset's native passthrough.

The odd part: the white balance snaps back to correct as soon as any Pico system
UI element is drawn on screen. Examples that trigger the correction:

• The room boundary / guardian border appearing when I get close to the edge of my play space
• The wrist menu circle that appears when I flip my hand over

While one of those elements is visible, passthrough looks correct. The moment it
disappears, the boosted white balance returns.

Steps to reproduce

1. Open ALVR on the Pico 4 Enterprise
2. Observe the passthrough menu while waiting to connect

Expected: passthrough white balance stays consistent and matches the
headset's native passthrough, with or without system UI on screen.

Actual: passthrough is white balance boosted except while a Pico system UI
element is visible.

Hardware

Issues seems to be independent of the PC since it shown on the waiting to connect screen.

Headset: Pico 4 Enterprise (OS version: 5.13.7.S)

Tested on latest stable release of ALVR (20.14.1)