Engineering analysis

Manufacturing-readiness checks and geometry repair: wall-thickness analysis for sheet metal, casting, or 3D-printing; pairwise clearance and interference checks between assembly components; and ShapeFixer-based healing of imported or non-watertight geometry.

Entries

check-thickness · analyze-clearance · heal

check-thickness

UV-grid sample each face and cast an inward ray to the opposite wall; reports min/max/mean thickness and flags all samples below a minimum acceptable threshold.

Input — Flag-form or JSON-form (stdin or argv path).

Parameters

Returns — JSON object with minThickness, maxThickness, meanThickness (or null if no samples), thinRegions (array of flagged sample locations), and samples (count).

Example

occtkit check-thickness part.brep --min-acceptable 1.5 --sampling-density fine

{
  "ok": true,
  "minThickness": 1.1,
  "maxThickness": 4.8,
  "meanThickness": 2.9,
  "thinRegions": [
    {
      "centerPoint": [10.5, 20.3, 5.1],
      "thickness": 1.1,
      "faceRefs": ["face[3]"]
    }
  ],
  "samples": 256
}

Drives — Face.uvBounds, Face.point(atU:v:), Face.normal(atU:v:), Shape.intersectLine(origin:direction:).

Notes — fine increases accuracy at the cost of speed; use coarse for a quick sanity check on large bodies.

analyze-clearance

Pairwise minimum-distance and interference check between two or more BREPs; each pair gets a minDistance and optional contact points, with interferenceVolume reported when bodies intersect.

Input — Flag-form or JSON-form (stdin or argv path).

Parameters

Returns — JSON object with pairs array. Each pair contains: a, b (file paths), minDistance, intersects (bool), belowMinClearance (bool or null if no threshold), contacts (array of point pairs), interferenceVolume (volume of overlap, or null for non-solid pairs or when not intersecting).

Example

occtkit analyze-clearance shaft.brep housing.brep bearing.brep --min-clearance 0.1

{
  "ok": true,
  "pairs": [
    {
      "a": "shaft.brep",
      "b": "housing.brep",
      "minDistance": 0.05,
      "intersects": false,
      "belowMinClearance": true,
      "contacts": [
        {
          "fromPoint": [10.0, 0.0, 5.0],
          "toPoint": [10.05, 0.0, 5.0],
          "distance": 0.05
        }
      ],
      "interferenceVolume": null
    },
    {
      "a": "shaft.brep",
      "b": "bearing.brep",
      "minDistance": 0.0,
      "intersects": true,
      "belowMinClearance": true,
      "contacts": [],
      "interferenceVolume": 2.3
    }
  ]
}

Drives — Shape.allDistanceSolutions(to:), Shape.intersection(_:), Shape.volume.

Notes — A minDistance of 0 means bodies touch; negative values indicate interference (overlap). interferenceVolume is meaningful only for solid×solid pairs.

heal

Heal imported or non-watertight geometry via OCCT ShapeFixer; reports before/after Shape.analyze() snapshots so the caller can verify the heal changed something.

Input — Flag-form or JSON-form (stdin or argv path).

Parameters

Returns — JSON object with outputPath, before and after health snapshots (each with faceCount, edgeCount, freeEdgeCount, smallEdgeCount, smallFaceCount, selfIntersectionCount, isValid), fixes (counts of resolved issues), and warnings (array).

Example

occtkit heal imported.brep --output imported_healed.brep --tolerance 0.01

{
  "ok": true,
  "outputPath": "/tmp/imported_healed.brep",
  "before": {
    "faceCount": 24,
    "edgeCount": 72,
    "freeEdgeCount": 3,
    "smallEdgeCount": 2,
    "smallFaceCount": 1,
    "selfIntersectionCount": 0,
    "isValid": false
  },
  "after": {
    "faceCount": 24,
    "edgeCount": 72,
    "freeEdgeCount": 0,
    "smallEdgeCount": 0,
    "smallFaceCount": 0,
    "selfIntersectionCount": 0,
    "isValid": true
  },
  "fixes": {
    "smallEdgesFixed": 2,
    "smallFacesFixed": 1,
    "freeEdgesClosed": 3,
    "selfIntersectionsResolved": 0
  },
  "warnings": []
}

Drives — ShapeFixer (setPrecision, setMaxTolerance, setMinTolerance, perform), Shape.analyze(), Shape.isValid.

Notes — Per-fix --fix-* flags are accepted today for forward compatibility with the issue spec but currently all coalesce into ShapeFixer’s precision tuning. Granular per-fix gating awaits an upstream OCCTSwift API. If ShapeFixer.perform() reports no changes, both snapshots may be identical.