# Helios Benchy public result package

This package accompanies https://iphonotype.com/Helios-Benchy/.

The primary benchmark compares one 72-view Helios reconstruction of target
PF-T31-00001059-C694BB02 with the matching FULL_BORE_v1 corrected scan-visible
CAD reference. The four-system context adds registered iPhone 17 Pro Max,
iPhone 15 Pro Max, and iPhone 12 Pro Max reconstructions scored against the
same 55,622-point CAD sample. The reference is CAD-derived and is not a
CMM-measured physical mesh. Results combine physical print and seating
deviation, reconstruction, registration, occlusion, and sampling.

The four columns are contextual pipeline evidence, not a controlled sensor-only
ranking. Helios and the iPhone 12/17 runs retain fixed metric scale during CAD
alignment; the iPhone 12/17 scale comes from four AprilTags. The iPhone 15
column retains its package-authored plate scale and bounded plant alignment,
then applies the common nearest-neighbour and extent definitions. Capture
durations exclude reconstruction and 3DGS training time.

Files specific to that comparison:

- downloads/device-comparison.json: sanitized metrics, recovery, capture, and registration provenance
- downloads/device-comparison.csv: flat same-CAD comparison table
- data/viewer-iphone12.json, data/viewer-iphone15.json, data/viewer-iphone17.json: registered scan coordinates and absolute CAD residuals for the browser viewer

The iPhone 12/17 clouds are sparse SfM outputs, so their retained scan points
can have low scan-to-CAD residuals while difficult CAD surfaces remain missing.
Read those residuals together with CAD-to-scan distance and CAD coverage. The
iPhone 15 geometry scored here is the Apple Object Capture photogrammetry mesh,
not LiDAR and not the package's Gaussian-splat rendering.

The projection-angle result is an image-space redundancy screen. It identifies
24 views as the first subset to reconstruct but does not establish reduced-view
3D equivalence. See subset-rerun-plan.csv for the required confirmation design.

Public files omit local paths and ambiguous secondary volume fields. The Helios
viewer contains all 16,274 registered target-prism scan points plus a
deterministic 8,000-point CAD surface sample; it does not enrich the largest
residuals. The iPhone viewer datasets retain every registered target point used
for their normalized point residual display. Signed-normal residuals are
available only for Helios.

In helios-cad-overlay.ply, class_id 0 identifies CAD samples and class_id 1
identifies registered Helios scan points. The error_mm field is zero for the CAD
samples and carries scan-to-CAD distance for Helios points.

SHA256SUMS paths are relative to the page root. Verify an intact page folder with:

    cd Helios-Benchy
    shasum -a 256 -c downloads/SHA256SUMS

The interactive viewer uses a local copy of Three.js and OrbitControls under
the MIT license; see vendor/THREE-LICENSE.txt.