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Chassis slip-angle telemetry — source development

This optional, read-only vehicle telemetry estimates signed chassis travel angle relative to its nose from the actual Chaos rigid-body planar forward and lateral velocities. It is not tire slip angle, a suspension model, a racing control assist, a verified drifting system or a safety instrument.

  • Positive values mean movement toward the car's right side; negative values mean movement toward the left while moving forward.
  • Accepted samples require 1–250 ms frames, finite local motion, forward speed of at least 300 cm/s and planar speed no greater than 10000 cm/s. Reverse, near-stationary, excessive or malformed frames clear the live display without manufacturing session peaks.
  • On spacious expanded-desktop layouts (at least 28 telemetry rows), the live HUD shows a ~120 ms smoothed estimate; smaller desktop windows omit this optional line to preserve genuine lap/sector feedback. Finished Results show the maximum absolute raw angle and sampled time with at least 12 degrees of chassis direction difference while traveling forward at 900 cm/s or faster. These thresholds are presentation choices, not handling physics or tire-grip validation.
  • Restart clears all stats; pause, focus loss, invalid Chaos state and teleport remove live readings while preserving valid same-run peaks.
  • The meter never changes throttle, steering, braking, race clock, lap completion, rewards, credits, records or save-game data. Compact Android HUD retains priority for driving controls, genuine timing and route hints.

Portable verification

cmake -S Tests/Standalone -B Tests/Standalone/build -DCMAKE_BUILD_TYPE=Release
cmake --build Tests/Standalone/build --config Release
ctest --test-dir Tests/Standalone/build -C Release -R '^ChassisSlipAngleMeter$' --output-on-failure
python3 -m unittest discover -s Tests/Editor -p 'ChassisSlipAngleBindingTests.py' -v

Tests cover signed 45-degree motion, temporal smoothing, slow/reverse rejection, nonfinite/overspeed/long-frame rejection, interruption and restart behavior, and 20,000 fixed-memory samples. Source integration tests check that real Unreal chassis velocity projections feed the policy and that the HUD is observational.

Required real-world acceptance

  1. Compile actual licensed UE 5.8 Editor and Game targets with UHT, record the compiler, exact engine fingerprint and source commit hash.
  2. Cook the owned circuit, package a real Windows executable and physically install it. Cross-check telemetry direction on straight, turning, sliding, braking and reversing chassis movement in both handling modes.
  3. On a genuine Android installation verify compact HUD still prioritizes steering, GAS/BRAKE, pause and recovery during landscape/orientation changes and OS focus interruption.
  4. Check teleport/recovery and paused timing never leave stale live angle. Compare displayed angles with recorded world velocity and actor yaw; log source/engine/package hashes, observed numeric ranges and any glitches.

Portable CI is not an Unreal compile, cooked map, executable or device playtest. Do not publish this as verified playable functionality until the existing game release gate #148 is genuinely satisfied.