Scan Align

Seed ?

Import

ScanSTL · OBJ · PLY · GLB/GLTF · XYZ/PTS/CSV

Scan units Reference units

Reference (CAD or 2nd scan)same formats — tessellated CAD export

STEP / IGES are exact B-rep formats and are not supported in a browser. Export the CAD as a fine binary STL (or OBJ/PLY) from Fusion 360 / SolidWorks and load that.

Scan

Not loaded.

Reference

Not loaded.

Clean scan ?

Statistical outlier removal ?

k neighbours n · MAD

Radius outlier removal ?

radius mm (0 = auto) min neighbours (0 = auto)

Remove ground plane / table (RANSAC) ?

tolerance mm (0 = auto) also below

Remove small islands (meshes) ? min island size, % of largest Crop box (scan coordinates, mm)

Lasso selection is not available — use the crop box and the island filter.

Initial (global) alignment

PCA / OBB — all 24 proper axis permutations ? FPFH + RANSAC + max-clique + FGR ?

feature points RANSAC iterations

Denoise for features only (MLS plane projection) ? Estimate uniform scale (Umeyama) ?

Manual point pairs (Horn/Umeyama)

0 pairs

Click a point on the scan, then the matching point on the reference. Snaps to the nearest vertex. 3+ pairs.

Datums (3-2-1 / RPS)

Dataset Feature

Region box (dataset coordinates, mm, relative to its centroid). Leave empty for all points.

tolerance mm (0 = auto)

Planes are used in fitting order: 1st → Z (primary), 2nd → X (secondary), 3rd → origin. If both frames are set, a datum-to-datum candidate is added to the initial alignment.

Fine alignment (multi-scale ICP)

Objective Robust kernel Trimming Max normal angle ° Max iterations / level Reject boundary matches

Correspondences are exact point-to-triangle (BVH) for mesh references. Kernel scale = 1.4826·MAD of residuals (floored at the noise estimate). Coarse level uses Huber, no trimming and no normal rejection to widen the convergence basin.

Lock degrees of freedom (reference axes)

Weighted regions (reference coordinates)

Manual nudge

step mm step °

Rotations are about the scan's centroid, in reference axes. A mouse gizmo is not provided — use the step buttons.

Self-verification

Synthetic self-test

noise % of size outliers % cropped % points

Transform (original file coordinates, mm)

Align first.

Aligned mesh

Format Frame

Origin-aligned frame from

Report

Opens a printable page (use the browser's Print → Save as PDF).

Algorithms used

Cleaning: hash vertex welding, degenerate/duplicate face removal, edge-topology report, statistical & radius outlier removal (median/MAD thresholds), RANSAC plane segmentation, island filter.
Noise: k-NN local plane-fit residual, median over points (dense surface samples for CAD tessellations).
Normals: PCA with adaptive k, MST-style propagation for orientation; curvature λ₀/Σλ.
Global: PCA/OBB × 24 proper permutations; FPFH; mutual NN; FGR tuple test; RANSAC (edge-length, distance, normal checks); TEASER++-style max-clique pruning; Fast Global Registration (Geman-McClure + GNC); Horn/Umeyama.
Fine: multi-scale ICP (3 levels), point-to-point / point-to-plane / symmetric point-to-plane / GICP, exact point-to-triangle via BVH, Tukey/Huber/Cauchy with MAD scale, trimmed ICP with auto overlap, normal/boundary/distance rejection, convergence & divergence detection, DOF locks, region weights.
Verification: full-resolution deviations, inlier ratio, normal consistency, 30-run multi-start stability, bidirectional CAD↔scan, split-half cross-validation, 6×6 information-matrix degeneracy analysis, covariance + bootstrap uncertainty, sanity checks, synthetic ground-truth test.
Not implemented: STEP/IGES import, colour-ICP, bilateral normal filtering, cone fitting, lasso/paint selection, mouse transform gizmo, non-rigid deviation analysis.

Deviation (mm) blue = under · green = in tolerance · red = over

Verdict

Not verified

Layers

Deviation map

in-tolerance ± mm range ± mm

Section & clipping

Section plane

Normal flip side

Offset

2D section overlay Clipping box (reference coords)

Measure

Worst areas

Run Verify.

Ready. Load a scan and a reference.