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Desktop racing instrument cluster — source QA

The Unreal race HUD now has a modest, asset-free instrument panel at the lower right of wide desktop viewports. It is a UI iteration, not production UMG/Slate work or proof of an installed racing game.

Presented values

  • Speed: actual player pawn reported speed, respecting the profile's km/h versus mph preference. The display caps nonsensical values to 999 km/h rather than letting text overflow.
  • Nitro: existing current-session boost charge, shown as a 0–100% bar.
  • Engine heat (arcade): measured game-model heat fraction, not a real vehicle sensor.
  • Chassis condition: 100% minus current race collision-damage fraction, not a vehicle safety rating or persistent save/garage attribute.

Every bar has a written label and percentage. The fill is never used to make racing or purchasing decisions.

Layout and safety contract

The panel is absent on Android, compact windows, short desktops, menus and finished races. All values and dimensions must be finite. The standalone layout policy computes panel geometry without engine headers and reserves a right-hand text lane, so long existing telemetry is truncated before encroaching on the instrument area. The widget sits above the desktop footer, and no new touch hit region or control ownership is introduced.

The rendering code may change presentation only. It must not mutate physics, drive controls, lap clocks, checkpoint ordering, credits or save data.

Verification

Source checks:

python -m unittest discover -s Tests/Editor -p '*Tests.py'
cmake -S Tests/Standalone -B build/test
cmake --build build/test --parallel
ctest --test-dir build/test --output-on-failure

Relevant portable test: HudInstrumentCluster, which sweeps desktop viewports and checks invalid/compact/touch/menu/results cases and bounds. Related source contract: HudInstrumentClusterBindingTests.py.

A qualified Unreal Engine 5.8 Editor/UHT build and real Windows/Android installs are still required before claiming gameplay, font metrics, high-DPI screenshots, contrast testing or frame-time performance. See playable-release gate and production UI issue.