Mimir

Realtime cameras, microphones, chirplets, and field evidence organized into one coherent stream machine.

Move Calibration Protocol

4 min read

Move Calibration Protocol

Mimir owns Move calibration and sensor fusion. Muninn owns source-local facts: camera marker candidates, USB controller IMU/button state, and local Move light commands. Odin discovers and projects the surfaces. Fensalir consumes Mimir’s resolved poses after Mimir has earned them.

Current Stream Shape

  • Starfire should run Muninn as a local capture/control daemon. Its Move stream address is muninn:starfire:move-evidence.
  • Nightwing runs Muninn for its USB Move and local camera witnesses. Its Move stream address is muninn:nightwing:move-evidence.
  • Mimir on Starfire publishes resolved pose frames at mimir:starfire:move-controller-poses.
  • Quest can participate as an external tracked VR reference over USB: quest:usb:headset-pose, quest:usb:left-controller-pose, and quest:usb:right-controller-pose.
  • Starfire ASIO/Scarlett loopback can provide cue timing, but it is not a Move pose authority.

The Move hot path is CultMesh stream frames. On the same host, those frames use shared-memory bytes rings. Across hosts, the remote peer still crosses the Verse/network boundary. The current Raven program media bridge is not same-host zero-copy into Mimir/Fensalir; it sends CultNet/CultMesh media documents and lowers to local UDP for OBS compatibility.

Required Capture Phases

  1. preflight-streams: hold both Moves still and visible; prove stream freshness, clock skew, and controller ids.
  2. dark-stillness: lights off, both Moves still; estimate gyro bias, gravity, and magnetometer baseline.
  3. lit-stillness: light one Move at a time, then both; map light commands to controllers and measure centroid stability.
  4. axis-sweeps: slow pitch/yaw/roll sweeps; fit gyro scale, accelerometer frame, and optical angular consistency.
  5. figure-eight: broad figure-eight motion; fit magnetometer hard/soft iron and cross-axis coupling.
  6. quest-reference: optional Quest headset/controller reference with the Move between the two Quest controllers in front of the headset.
  7. validation-pass: held-out free motion; promote only if triangulated optical residuals and IMU prediction residuals pass.

Quest Access Preflight

The Quest must be authorized for USB debugging before Starfire Muninn can query it. Muninn owns the access surface:

muninn serve --store C:\Meta\Odin\state\muninn.telemetry.cc --host starfire --quest-adb --quest-serial 1WMHHB68PG1515

When the Quest is authorized, Muninn publishes muninn.quest_access.v1 and advertises muninn:<host>:quest-input, muninn:<host>:quest-poses, and muninn:<host>:quest-warped-video-input. Mimir consumes the access/pose surfaces as calibration evidence; it does not own Quest USB access.

muninn quest-access-status --store C:\Meta\Odin\state\muninn.telemetry.cc

ADB authorization proves USB access, device identity, and basic headset state only. It does not expose Quest headset or controller poses; those still require a Quest/OpenXR witness bridge that publishes pose samples through Muninn. The current calibration protocol can still run without Quest, but Quest poses are the preferred external reference when the headset and both controllers are sitting around the Move.

Data Products

  • mimir.move_fusion_rig_calibration.v1: camera intrinsics/extrinsics, clock association policy, and gyro unit scale.
  • mimir.move_imu_calibration.v1: per-controller gyro bias/scale, accelerometer gravity frame, magnetometer correction, and noise estimates.
  • mimir.move_controller_identity_map.v1: stable association between Muninn USB ids, light receipts, and optical orb identities.
  • mimir.move_calibration_receipt.v1: sample counts, residuals, rejected phases, and promotion decision.

Optical Sphere Fit Authority

MimirMoveSphereCalibrationFitter owns the bounded two-Eye optical fit after a collection session reaches Fitting. Eye 0 defines the tracking-space gauge. The fitter jointly estimates both focal lengths and Eye 1’s rigid pose from same-frame, same-Move correspondences, using a deterministic 80/20 training and held-out partition. A robust training consensus may reject contaminated marker pairs, but promotion also requires at least 65 percent of the untouched held-out pairs to agree and must pass the session’s median and P95 reprojection limits.

The physical orb radius is an explicit input; it is never guessed by the solver. PSMoveAPI’s reported blob radius is a color-segmentation result, not a calibrated sphere silhouette. It may seed or weight depth only after the per-camera radius response has been validated. A fresh PSMoveAPI position age is also not optical confidence and must not be interpreted as one.

Preflight Command

dotnet run --project .\src\Mimir.BufferSmoke\Mimir.BufferSmoke.csproj -- --move-calibration-protocol-smoke --output artifacts\move-calibration\protocol.cc

That writes the typed protocol as mimir.move_calibration_protocol.v1 into a CultCache receipt. The real hardware runner should consume this document plus Muninn’s muninn.quest_access.v1 when Quest is available, then append capture receipts instead of inventing a parallel checklist.