3MF Medical Surgical Guides & Implants (.3mf)

@modelscript/three-mf (languages/three-mf) provides native WebAssembly parsing, half-edge 2-manifold watertightness and Euler-Poincaré characteristic ($\chi =V-E+F$) verification, surgical guide minimum wall-thickness and drill-sleeve K-wire clearance auditing, osteotomy cutting-plane normal validation, DAEBuilder lowering, and ISO 10303-21 STEP / OpenSCAD projections for ISO/ASTM 52915 3MF Medical patient-specific 3D-printed surgical guides and cranial/orthopedic implants.

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Supported Extensions & Standards

Extension	Format	Description
.3mf	ISO/ASTM 52915 3MF	3D Manufacturing Format (<model>, <resources>, <mesh>, <vertices>, <triangles>, <build>, and surgical guide/implant metadata)

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Key Capabilities

1. Watertight 2-Manifold Topology & Signed Divergence Volume

• Constructs the mesh half-edge incidence graph to verify that every triangle edge is shared by exactly two oppositely oriented faces (zero boundary holes, zero non-manifold edges, zero degenerate zero-area triangles).
• Computes exact signed divergence volume, surface area, connected shells, genus $g$, and Euler characteristic $\chi =V-E+F=2(1-g)$.

2. Surgical Cutting Guide & Drill-Sleeve Verification

• Validates patient-specific osteotomy cutting guides and pedicle/dental drill sleeves:
  • Enforces minimum structural wall thickness ($\ge 1.2\text{ mm}$ for biocompatible PA12 / Formlabs BioMed resins) and positive drill-guide sleeve radial wall thickness ($r_{\text{outer}}-r_{\text{inner}}\ge 1.0\text{ mm}$).
  • Verifies unit-normalized osteotomy cutting-plane normals ($\parallel \mathbf{n}\parallel =1$) and drill trajectory vectors.

3. ISO 10303-21 STEP & OpenSCAD Export

• Exports verified surgical guides and implants to ISO 10303-21 STEP (threeMfToStep) and OpenSCAD (threeMfToScad).

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Pre-Flight Diagnostics

10 rules10 error

Code	Rule	Severity	Message
M9701	three-mf-non-manifold-edge	error	Mesh in object '<objId>' is not a closed 2-manifold ('<openEdges>' open boundary edges, '<nonManifoldEdges>' non-manifold edges).
M9702	three-mf-degenerate-triangle	error	Triangle #<triIndex> (<v1>, <v2>, <v3>) in object '<objId>' is degenerate (duplicate vertex indices or zero area).
M9703	three-mf-negative-mesh-volume	error	Mesh in object '<objId>' has non-positive signed volume '<signedVol> mm^3' (inverted outward face normals).
M9704	three-mf-unresolved-build-object	error	Build '<item>' references undefined resource '<object id="<objectId>">'.
M9705	three-mf-wall-thickness-violation	error	Surgical guide or cannula '<targetName>' has wall thickness '<actualMm> mm' below minimum additive manufacturing threshold '<minMm> mm'.
M9706	three-mf-invalid-osteotomy-guide-axis	error	Osteotomy plane or drill sleeve '<guideFeatureId>' on object '<objId>' has a zero-length normal/axis vector.
M9707	three-mf-missing-biocompatible-material	error	Medical object '<objId>' lacks an approved ISO 10993 / USP Class VI biocompatible material (found '<matName>').
M9708	three-mf-singular-item-transform	error	Build '<item objectid="<objectId>">' has singular or reflection 4x3 affine transform with determinant '<det>'.
M9709	three-mf-out-of-bounds-vertex-index	error	Triangle #<triIndex> (<v1>, <v2>, <v3>) in object '<objId>' references vertex index outside [0, <value>].
M9710	three-mf-duplicate-object-id	error	Duplicate '<object id="<objId>">' declared in '<resources>'.

Generated from languages/three-mf/src/lints/rules.ts. All languages →

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CLI Usage

# Inspect 3MF objects, build items, and surgical guide metadata
msx three-mf inspect MandibleOsteotomyGuide.3mf

# Validate 2-manifold watertightness, wall thickness, and osteotomy planes
msx three-mf validate MandibleOsteotomyGuide.3mf

# Compute mesh topology metrics (Euler characteristic, volume, surface area)
msx three-mf topology MandibleOsteotomyGuide.3mf

# Export surgical guide mesh to ISO 10303-21 STEP or OpenSCAD
msx three-mf to-step MandibleOsteotomyGuide.3mf > MandibleOsteotomyGuide.stp
msx three-mf to-scad MandibleOsteotomyGuide.3mf > MandibleOsteotomyGuide.scad