[BUG] Right eye re-redering as a square on top of image #439

Describe the bug

Injecting into Assetto Corsa Rally (v0.6, UE 5.6.1, Steam build 25170642) renders the right eye into a sub-rect of the screen instead of the correct full eye view — visible as a corner/strip artifact on the flat mirror and in the HMD. It scales with game resolution (roughly quarter-screen at 4K, a thin strip at 1080p), pointing at the eye-rect/classification math rather than a game-side render. Native rendering method is usable but broken this way; Synchronized Sequential and Alternating (AFR) both hard-crash instead (FViewport::Draw called on a viewport with a different vtable! → access violation at acr.exe+0x2cf0054). This started with the game's v0.6 update (UE bumped to 5.6.1); the same UEVR build worked correctly on the prior UE version.

Log evidence points at the same root cause described in PR #422 ("Fix doubled stereo image on UE 5.5/5.6"): m_has_double_precision is true for this game ([UE5 Detected] Detected Double precision ADDSD), and instrumenting on_pre_calculate_stereo_view_offset via a Lua script confirms INDEX_NONE (-1) is only emitted once early, then steady-state view indices are exclusively 0 and 1 — the exact condition that leaves view 0 misclassified as is_full_pass. A Lua UObject scan also ruled out a game-side cause: exactly one viewport draw and one slate draw per frame, one

Also present, independently: [FViewport] Failed to find GetViewportSizeXY index, and [FFakeStereoRenderingHook.cpp:3891] Bad root or command list, falling back to Slate thread hook on every launch.

Upload logs and any crash dumps

log.txt

Identify the UEVR version

Tag 1.05, 195 commits past tag, commit 4ee5c6b, build date 30.08.2026 (latest public nightly, build 01143).

To Reproduce

1. Launch Assetto Corsa Rally v0.6 (UE 5.6.1), let it reach the main menu.
2. Inject with UEVR, Native rendering method, OpenXR runtime.
3. Observe: a secondary/duplicate view renders in the top-right of the screen, both in the main menu and in-car, in each eye in the HMD.
4. Switching rendering method to Synchronized Sequential or Alternating (AFR) crashes on inject instead.

Expected behavior

Each eye shows the correct single full eye view with no secondary sub-rect artifact — matching behavior from before the game's v0.6/UE 5.6.1 update.

Screenshots

PC Specs

• OS: Linux (CachyOS, Arch-based), kernel 7.2.3-1-cachyos, via Proton (vkd3d-proton 3.1 + DXVK) — not Windows, flagging since this report is off the beaten path, but the described bug is engine-side (matches PR Fix doubled stereo image on UE 5.5/5.6 (zero-based eye index misclassified as full pass) #422), not Proton-specific
• Graphics card: AMD Radeon RX 9070 XT
• CPU: AMD Ryzen 7 5800XT (8-Core)
• Headset: Meta Quest 3
• OpenXR
• Streamer: Steam Link
• OpenXR runtime: SteamVR