openscad-model-qa

name	openscad-model-qa
description	Audit OpenSCAD models for renderability and print-readiness. Use when discovering part selectors, exporting printable STL smoke tests, rendering PNG previews, checking CGAL or Manifold logs, or summarizing printability risks before release or handoff.
argument-hint	SCAD file or folder, target parts, desired outputs (STL or PNG), print orientation, backend, and any acceptance criteria

OpenSCAD Model QA

Use this skill when the goal is to verify a model, not necessarily redesign it. It covers selector discovery, deterministic renders, representative STL exports, and printability triage.

If the environment cannot resolve includes or OpenSCAD itself is missing, use the openscad-toolchain-setup skill first. If QA finds geometry that must be redesigned to avoid supports or fix print defects, switch to the openscad-support-free-fdm skill.

Inputs To Confirm

Before running QA, confirm:

• target SCAD file or folder
• which part selectors matter for the review
• whether the deliverable is printable STL, documentation PNG, or both
• intended print orientation for each printable part
• whether to use default CGAL behavior or --backend=manifold
• whether assembly, xray, or envelope views exist and should be checked
• any must-meet dimensions, fit targets, or no-support requirements

Default Bias

• Prefer checking printable part selectors before assembly previews.
• Prefer deterministic command-line renders over manual GUI-only inspection.
• Treat successful STL export and readable logs as the minimum gate.
• Treat printability review as part of QA, even when the user only asked for a render.

Workflow

1. Discover the controlling entrypoints.

   • Find the part selector and its documented options.
   • Separate printable selectors such as tray, face, top, bottom, module, or print_set from preview selectors such as all, all_preview, assembled, xray, or envelope.
   • If the file has no selector comments, identify the smallest representative export path directly from the code.

2. Run the cheapest smoke export.

   • Export one representative printable part first.
   • Use -q for cleaner logs and save the STL to /tmp or another scratch path.
   • If the model is boolean-heavy or CGAL is unstable, rerun with --backend=manifold.

3. Render a deterministic inspection image when visual QA matters.

   • Use explicit --imgsize, --camera, and --colorscheme values.
   • Prefer preview or xray selectors for visual inspection, but do not confuse them with printable geometry validation.
   • Keep the camera fixed between before and after comparisons.

4. Inspect logs and geometry outcomes.

   • Check for parser errors, missing includes, warnings, and unexpected volume counts.
   • In this workspace, validated single-part exports commonly report CGAL Volumes: 2, while both-style two-piece exports commonly report Volumes: 3.
   • Treat any mismatch between the intended part and the exported geometry as a QA failure even if OpenSCAD exits successfully.

5. Triage printability risks.

   • Check orientation-dependent overhangs, horizontal bores, trapped cavities, thin walls, tiny tabs, unsupported bridges, and buried fastener features.
   • Note whether the model is printable as-is, printable with a named orientation, or blocked pending redesign.
   • If the fix requires topology changes, hand off to the support-free FDM workflow instead of improvising ad hoc geometry edits.

6. Close with an evidence-based verdict.

   • Record the exact commands used.

Decision Points

• If include resolution fails, stop and use the toolchain setup workflow.
• If only preview selectors exist, still force at least one exportable geometry path before calling the model validated.
• If the model exposes xray or assembled selectors, use them for visual inspection but keep printable selectors as the acceptance path.
• If a multi-part export intentionally contains separate printed bodies, expect multiple volumes and judge the result against the intended layout rather than a single-volume assumption.
• If QA reveals support-heavy geometry, split the task: QA documents the risk, and support-free FDM handles the redesign.

Completion Criteria

• controlling selector list is identified
• at least one representative printable STL export succeeds for each touched model
• deterministic PNG render succeeds when visual QA is requested
• logs were checked for warnings, errors, and unexpected volume counts
• intended print orientation is stated for printable parts
• final report clearly says pass, fail, or pass-with-risks

Resources

• Render QA checklist
• Command recipes
• Workspace QA notes