---
created: 2026-03-23T00:04:21.688Z
title: Milestone 2.0 live IPD change and SteamVR slider
area: general
files: []
---

## Problem

Current milestone (1.0) focuses on proximity detection. The next milestone (2.0) needs to address two related IPD goals:

**Primary goal:** Create an avenue for live software IPD change on the Beyond HMD. Users should be able to change HMD IPD in SteamVR without restarting SteamVR. The mechanism should be similar to how `beyond_prox_ctl.exe` runs debug commands against the driver via the named pipe interface. The official Bigscreen Beyond Utility would leverage this avenue to send IPD change commands to the driver.

**Secondary goal:** Get SteamVR to show its built-in IPD change slider UI, and have that slider work with the Beyond HMD while this driver is running. This would provide a native SteamVR experience for IPD adjustment.

## Solution

- Extend the existing named pipe command interface (used by `beyond_prox_ctl.exe`) to accept IPD change commands
- Driver receives IPD value via pipe, updates `Prop_UserIpdMeters_Float` on the HMD without requiring SteamVR restart
- Investigate SteamVR's `Prop_UserIpdMeters_Float` and related properties to determine what triggers the built-in IPD slider UI to appear
- Bigscreen Beyond Utility would call the same pipe interface to set IPD
- Research whether `IVRProperties::SetFloatProperty` triggers live updates or if additional SteamVR API calls are needed