openscad

# OpenSCAD Build a useful object from the user's real measurements and intended process. The starter is a drawer-organizer family, not a prescribed shape. For multi-part mechanisms requiring a true B-rep/STEP deliverable, choose a suitable CAD workflow instead of relabeling an STL. Before authoring a checked project, read [references/design.md](references/design.md) for the source interface, requirement schema and probe semantics. Keep the brief and limits in `design.json`; implement `module part(id, …named parameters…)` in `model.scad`. The builder calls each part with the saved variant values; it ignores top-level preview geometry. Declared input files are the only sources copied into the portable project. Compile trusted SCAD only; this is not a sandbox. Ask for missing measurements that would change the result. Otherwise state assumptions and make progress. For a mating fit, useful variants often differ only in clearance; a small fit coupon can save a full print. Never call a generated coupon a completed physical test. ```sh sh "$OPENSCAD_SKILLS/openscad/scripts/render-part.sh" node "$OPENSCAD_SKILLS/openscad/scripts/serve-handoff.mjs" "$HARNESS_WORKSPACE" ``` Requires Node 20+ and a separately installed OpenSCAD (tested 2021.01); set `OPENSCAD_BIN` for a custom location. The second command prints a loopback-only URL. Open that URL for variant comparison, native top/front/side sections, individual print-oriented STLs, the measured report and `handoff/project.zip`. It remains a saved snapshot after edits; rebuild before relying on it. The main CAD pane displays the selected `design.preview` part as `part.stl`. The helper renders every variant and part, checks repeat exports agree, then measures the actual saved mesh: closure/orientation/surface-shell count, required bounds/volume, empty clearance regions, required material and optional relative-part overlap. It orients individual STLs, moves them onto the bed, checks the declared build envelope and natively reimports them. Section planes are explicit; silhouettes are labelled. Outputs publish only after all checks and source-hash checks pass. A build lock prevents competing writers; previous outputs live in `.harness/history/`. Inspect `.harness/build.log` and `.harness/failed-mesh.json` after a failure. Do not remove a lock until its owner process has stopped. Inspect the actual STL in the CAD Viewer (orbit, section/measure when useful), not a source-code screenshot. Review the handoff on the intended screen size and make a substantive revision. Keep the user's requirements fixed while correcting geometry. Test that a known obstruction or missing material is rejected; do not weaken checks to obtain a green verdict. The ZIP includes source, variant wrappers, all exported parts/views and standalone rebuild tools. Extract it and run `node rebuild/build.mjs .` with Node and OpenSCAD installed; no Harness account or npm packages are required. `preview.scad` opens the selected editable configuration in OpenSCAD; `handoff/source-previews/` contains the other configurations. These preserve design coordinates; downloadable STLs use print coordinates. Checks cover only declared probe regions, not global minimum thickness or every self-intersection. They do not certify strength, slicing/supports, packed-plate capacity, food safety or real fit. Separate the digital evidence, process assumptions and physical testing still needed. A legacy `model.scad` without `design.json` renders a geometry preview with readiness false.