feat(viz): LiDAR sensor mount offset

[WomB0ComB0]

Summary

LidarScan.scan(origin, rot?, mountOffset?) now accepts an optional drone-local mount offset (e.g. [0, 0.5, 0] for a sensor on a 0.5 m mast). The offset is rotated into world space by rot and added to origin to produce the actual scan origin.

Mechanics

• Hoists the q→3x3 rotation matrix outside the existing per-ray loop so it can be reused for both the mount-offset transform and the direction rotation. No new compute cost on the scan side — the matrix already needed to exist; offset application is one matrix-vector multiply per scan.
• Hit positions now derive from this._origin (the post-offset scan origin) rather than the raw origin parameter — without this, a mast-mounted sensor would report hits as if rays started at the drone center but ended at the mast tip.
• Backward-compatible. Existing effects.ts:_updateLidar keeps passing two args; mountOffset defaults to undefined and the bare drone-origin path stays bit-identical to PR feat(viz): per-drone LiDAR scans #80.

Tests

Three new cases in client/__tests__/lidar.test.ts:

• World-axis-aligned offset (no rot)
• Rotation of offset by quaternion (yaw 90° → +X local maps to −Z world)
• Bare-origin path unchanged

Suite goes 14 → 17 tests, runtime unchanged (~380 ms).

Bundle

Main 756.4 → 756.6 KB (+200 B; 92 % of cap).

🤖 Generated with Claude Code

Summary by CodeRabbit

Release Notes

• New Features

  • Added mount offset support for LIDAR scans, enabling accurate hit position reporting from sensors positioned off-axis from the origin point. Mount offsets can be configured with optional rotation transformations for proper world-space alignment.

• Tests

  • Added comprehensive test coverage for mount offset behavior with and without rotational transformations.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 66e7a6e2-a645-4f77-af62-f5abf2f2883b

📥 Commits

Reviewing files that changed from the base of the PR and between a9f32a9 and 2ed332e.

📒 Files selected for processing (2)

• src/ResQ.Viz.Web/client/__tests__/lidar.test.ts
• src/ResQ.Viz.Web/client/webgpu/lidar.ts

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📝 Walkthrough

Walkthrough

Introduces an optional mountOffset parameter to the LidarScan.scan() method, enabling mast-mounted LIDAR sensors to report hits relative to an effective scan origin. The offset can be applied as world-axis-aligned or rotated via a quaternion, with corresponding test coverage validating both application modes.

Changes

Cohort / File(s)	Summary
Mount Offset Tests src/ResQ.Viz.Web/client/__tests__/lidar.test.ts	New test suite for LidarScan mount-offset behavior: validates hit positioning with no offset, world-axis-aligned offset, and rotation-aware offset application.
Mount Offset Implementation src/ResQ.Viz.Web/client/webgpu/lidar.ts	Extended scan() signature with optional mountOffset parameter; hoists quaternion→matrix computation for reuse in both offset rotation and per-ray direction transformation; snapshots mutable this._origin to ensure hit positions use the effective scan origin.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• perf(viz): hoist 2*q.xyz outside LiDAR rotation loop (PR #75 follow-up) #76: Also modifies LidarScan.scan() in src/.../webgpu/lidar.ts to hoist quaternion→matrix computation for ray rotation, overlapping with the quaternion handling logic introduced in this PR.

Poem

🐰 A sensor mounted high, with offset and care,
Quaternions spin, vectors rotate in air,
The LIDAR now knows where it truly sits—
No more mast confusion, each scan precisely hits! 🎯

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'feat(viz): LiDAR sensor mount offset' directly summarizes the main change: adding mount offset support to LidarScan with world-axis-aligned and quaternion-rotated offset handling.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/lidar-mount-offset

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[gemini-code-assist]

Code Review

This pull request adds support for a mountOffset in the LidarScan.scan method, allowing hit positions to be calculated relative to a sensor's local position on a drone. The changes include logic to rotate the offset into world space and new unit tests to verify the coordinate math. A potential race condition was identified where the scan origin is read from a shared mutable buffer after an asynchronous operation, which could lead to incorrect results if multiple scans are performed concurrently.