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Tracker App Roll Creates Pan / Tilt Errors - Gimbal Lock

Summary

The MRMC Tracker App can produce inaccurate pan/tilt values when the phone is rolled significantly in landscape orientation. The chat described this as an iPhone / IMU singularity or gimbal lock problem: as the camera rolls past roughly 20-40 degrees, pan and tilt values start changing even when the operator is mostly rolling.

This page is marked Needs Review because the thread identifies the behaviour and workarounds, but not a confirmed software fix.

Symptoms

  • Imported tracker-app camera path has more pan and tilt than the operator recorded.
  • Rolling the camera changes pan and tilt numbers significantly.
  • Roll past 40 degrees causes unexpected pan/tilt values.
  • Pointing the tracker app directly down means rolling the camera may not detect roll.
  • Imported Flair camera gives unreal pan and tilt to the rendered camera path.

Community Guidance

[LIKELY] Keep the tracker camera close to level for accurate pan/tilt

For handheld capture intended for Flair import, avoid strong roll angles when possible. Keeping the camera level produced the most accurate pan/tilt reproduction in the reported tests.

Confidence: 0.72

[LIKELY] Restart/open the app in the intended starting orientation

One operator reported making a habit of completely closing and reopening the app in the location and orientation intended for recording. This may not solve roll singularities, but it is a useful tracker-app setup habit.

Confidence: 0.56

[NEEDS REVIEW] Treat heavy roll as an app/device limitation

The thread suspected the problem came from device orientation math, accelerometers/IMU limits, or gimbal-lock style behaviour. If a move depends on heavy roll, test the import path before the shoot.

Confidence: 0.68

WhatsApp Excerpts

Timestamp User Evidence
2026-03-12 18:11 Tom D "The more I ROLL the camera, for some reason TILT and PAN are also getting affected."
2026-03-12 18:31 Tom D "It's like the phone goes into gimbal lock in this situation."
2026-03-12 18:31 Timothy Heys Cerchio "Would seem like a strange 'singularity' kind of thing..."
2026-03-12 18:37 Timothy Heys Cerchio "So iPhone also has its own singularities!"
2026-03-12 18:38 Tom D "Any roll that the operator does past 20-30degrees really does start to induce inaccurate readings from pan and tilt."
2026-03-12 18:49 Tom D "If you point the Tracker App directly down ... the app won't detect any ROLL at all."
2026-03-12 19:22 Timothy Heys Cerchio "This is definitely the typical North/South Pole 'gimbal lock'."
2026-03-12 20:09 Niko "If the app only reads the device's accelerometers, it makes sense that it creates 'singularities' at certain angles."
2026-03-12 20:26 Tom D "The imported camera gives unreal pan and tilt to the resulting rendered camera path also."