OpenSCAD

1. Overview

Code-first 3D solid modelling from plain-text scripts. Output can differ between versions and geometry engines, so reproducing a result needs stated versions.

Category: Engineering & CAD.

2. Version and scope assessed

Version assessed: Source commit d7a210ed01e5db9f09a8164894b0d0b07d7f2c67; 3MF package/expectation inspection and binary STL information limits.

4. Principle profile

5. Fundamental requirements

6. Evidence and verification

• E1: The published 3MF import fixture opened as a three-member ZIP. Its model XML specifies millimeters and exposes one object with twenty vertices, thirty-six triangles and a build item referencing object 1. A separate color-export regression expectation contains four raw color values but is normalized text with an unbound namespace prefix, not a valid standalone XML package; that parse error is recorded. No geometry engine was run. (source), confidence high
• E2: The retained binary STL expectation contains eight triangles, has the expected 84+50*n byte length, and uses zero for every two-byte triangle attribute. The writer similarly emits normals/vertices and zero attributes with an OpenSCAD Model header. This output is a mesh representation, not a serialization of source parameters, construction history or semantic units. (source), confidence medium
• E3: Source files are independently readable, but external includes, libraries, version differences, and generated geometry were not reconstructed independently. (source), confidence medium
• E4: The modeling workflow is local and editor-independent. (source), confidence medium
• E5: Models may inform manufacturing, but geometry validation, units, tolerances, and release approval were not assessed. (source), confidence low
• sovereignty: A positive Sovereignty finding requires established E1, E2 and E4 in the declared scope. The existing access/exit/custody record for OpenSCAD does not establish all three minimums. The prior positive finding is withdrawn; recorded storage and portability strengths remain facts, not a verified failure. (source), confidence medium
• longevity: E3 is not established for OpenSCAD's existing essential-record scope. The previous Longevity finding is replaced by Not assessed, not a verified failure or a positive placeholder. (source), confidence medium
• locality: Core modeling and rendering run locally without a provider. (source), confidence medium
• transparency: The positive control observations above do not yet establish whole-scope E5. The methodology requires that minimum before a positive Transparency and Control finding; the previous positive finding is therefore withdrawn to Not assessed, not changed to Does not meet. (source), confidence medium
• E3: The independent 3MF/STL readers expose mesh geometry and units where represented, but STL does not preserve source parameters/construction meaning and one regression expectation is not standalone XML. Complete includes/fonts, source/version dependencies and equivalent generated geometry remain unestablished for the original parametric profile. (source), confidence medium
• E5: Manufacturing accuracy alone is not E5. The current evidence does not establish effective model/include execution authority, file/output overwrite control, previewed consequential changes or correction after lost source edits; backup and configuration boundaries remain open. (source), confidence medium
• E2: The former E2 Pass does not establish a replacement parametric workflow preserving source parameters, construction meaning, units and required dependencies. Mesh-only interoperability is a narrower result, not full-scope migration. (source), confidence medium

7. Migration and recovery

Native storage format: Programmatic CSG Plain-Text Scripts (.scad).

Synchronization or runtime model: Git Version Control.

Example export or inspection command (not verified against any particular version or data set): openscad -o part.stl model.scad

8. Architectural strengths

Established strengths and their scope are recorded in the evidence and assessment findings on this page.

9. Architectural limitations

• A 3MF mesh/package does not preserve the original SCAD construction program.
• The inspected STL has no semantic source-parameter/unit fields and no populated triangle attributes.
• A normalized regression expectation is not itself a portable 3MF package.

10. Assessment findings and remaining work

Verification scenario: Rebuild models offline with all imported libraries and fonts; export geometry, inspect the parameterised source, and compare results.

What may invalidate an overconfident claim: Avoid claims of universally identical meshes across engines and versions.

Documentation starting point: https://openscad.org/documentation.html

Evidence update: 23 October 2026

• Resolved: The published 3MF import fixture opened as a three-member ZIP. Its model XML specifies millimeters and exposes one object with twenty vertices, thirty-six triangles and a build item referencing object 1. A separate color-export regression expectation contains four raw color values but is normalized text with an unbound namespace prefix, not a valid standalone XML package; that parse error is recorded. No geometry engine was run. Source.
• Resolved: The retained binary STL expectation contains eight triangles, has the expected 84+50*n byte length, and uses zero for every two-byte triangle attribute. The writer similarly emits normals/vertices and zero attributes with an OpenSCAD Model header. This output is a mesh representation, not a serialization of source parameters, construction history or semantic units. Source.
• Open: Actual CGAL/Manifold equivalence, exported geometry reconstruction, parameter/color/unit losses in receiving tools, complete library/font dependency capture, source/version compatibility and crash backup behavior. E5 needs source/include execution and save/export overwrite authority, inspectability and backup/correction boundaries.

Assessment follow-up: These findings now appear in the application’s evidence and limitations. At the user’s request, existing eligibility and principle ratings are unchanged; E3/E5, principle consistency and blank-status fixes will be reconciled in the next pass. Reproduction details and retained inputs are in evidence/third-pass/batch-5/.

Human-readable criteria: Can an independent party preserve the source model, units, dependencies, and editable structure, reproduce the result, and exchange it without losing important design meaning?

Rating reconciliation: 24 October 2026

E3 and E5 remain Not Verified for the existing declared scope. Longevity and Transparency and Control are Not assessed pending their required minimums. Sovereignty is also Not assessed because the required access/exit/custody minimums are not all established. The prior E2 Pass is withdrawn; its essential-record migration comparison remains incomplete. This is a targeted evidence decision, not a finding that the product fails. Existing E1, E4 and Locality findings were not re-certified.

Remaining: Actual CGAL/Manifold equivalence, exported geometry reconstruction, parameter/color/unit losses in receiving tools, complete library/font dependency capture, source/version compatibility and crash backup behavior. E5 needs source/include execution and save/export overwrite authority, inspectability and backup/correction boundaries.

Next without installing locally: Retain a synthetic parametric model with every include/font and expected geometry/unit/color manifest, then use independent parsers and externally supplied engine comparisons. Review same-version file/execution/backup controls.

The individual decision and provenance are retained in evidence/rating-reconciliation/batch-6/. Overall: Insufficient evidence.

Individually reconciled in rating batch 6 on 24 October 2026. E3/E5 remain Not Verified for explicit missing coverage; dependent unsupported findings corrected. Previously resolved questions are retained, not counted again. E1/E4/Locality were not re-certified by this targeted review. The assessment procedure is described in the methodology.