knewnothing-git
cb6f984bbc
Blockers -------- 1. requirements.txt was missing scipy, networkx and lxml. With only trimesh/numpy/rtree installed the first measure of any mesh died with a raw ModuleNotFoundError from mesh.body_count, and .3mf could not load at all. Reproduced in a clean venv, then confirmed fixed there: all four advertised formats now load and measure. Only scipy is mirrored into requirements-dev.txt; networkx and lxml are already listed under the repo tests block, matching how trimesh is handled. 2. Wall thickness is now measured per connected body. Cast against a whole assembly, a ray can leave one body, cross a mating clearance and land on its neighbour, recording the fit gap as a wall - so a tight-clearance assembly reported a wall violation no single part had. _wall_facts splits first and measures each body against itself, pooling the results and adding a per_body breakdown. Sample budget is shared by surface area with a floor so small bodies are still sampled. Should-fix ---------- 3. Each fact family now runs through _safe and degrades to an error field. A planar mesh dies in convex_hull; previously that cost the user the whole report, including the facts that had computed. 4. New scale block reports bbox_diagonal_mm and units_suspect. A meters-scale mesh sits under the 0.1 mm on-plate tolerance, so every down-facing face reads as on-plate and the part looks like a flawless print. SKILL.md now branches on the measured field instead of asking the agent to eyeball the bounding box. 5. Added the skill to the README table and the docs page array. 6. process-limits.md now names which rows have a measured counterpart today (walls, self-supporting angle) and which do not (hole diameter, positive feature, unsupported bridge), closing the eyeballing loophole. SKILL.md also gained a rule to attribute an assembly's wall violation to the body it belongs to. Verification ------------ - Clean venv built from the skill's own requirements: 26 checks covering multi-body clearance, 81k-face performance, a 42-body assembly, planar, meters-scale, broken export, all four formats, degenerate mesh. - Per-body change costs ~150 ms on an 81k-face mesh (7493 -> 7643 ms); the bulk of that time is trimesh's pure-Python ray fallback, not the split. - Real part measurements unchanged: L-bracket still 1200 mm2 unsupported, 9.0 mm median wall. - gcode/urdf/dxf suites fail identically with and without this change; those are pre-existing.
96 lines
5.2 KiB
Markdown
96 lines
5.2 KiB
Markdown
---
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name: dfam-check
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description: Measure mesh files against Design for Additive Manufacturing (DfAM) rules and report printability findings per process (FDM, SLS, SLA/DLP, metal PBF, MJF). Use when the user asks whether a part is printable, wants overhang/wall-thickness/support analysis of an `.stl`, `.obj`, `.ply`, or `.3mf` mesh, wants a build-orientation recommendation, or wants DfAM redesign guidance before slicing with `$gcode` or regenerating geometry with `$cad`.
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---
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# DfAM Check
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Provenance: maintained in [earthtojake/text-to-cad](https://github.com/earthtojake/text-to-cad).
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Use the installed local skill files as the runtime source of truth; the
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repository link is only for provenance and release review.
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Use this skill to produce conservative, evidence-backed DfAM reports for mesh
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files before slicing or printing. It measures geometry facts locally and
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compares them against per-process design limits; it never slices, uploads, or
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starts print jobs.
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## Geometry Inspection
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Use `scripts/dfam_tool.py` in the active project Python environment for all
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geometry facts (requires `trimesh`, `numpy`, `rtree`). The tool is fact-only:
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it reports measurements and never emits pass/fail or readiness statuses.
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Comparisons and verdicts belong to this workflow. Do not estimate wall
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thickness, overhang angles, or support volume by eye or from renders when the
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tool can measure them.
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```bash
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python scripts/dfam_tool.py measure part.stl --angle-limit 45
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python scripts/dfam_tool.py orientations part.stl --angle-limit 45
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```
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Set `--angle-limit` to the target process's self-supporting angle from
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`references/process-limits.md` before measuring, and re-run when the target
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process changes: the aggregate support-area facts are binned against it.
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STEP/STP input is boundary-representation CAD, not a mesh. When the `$cad`
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skill is installed, export an STL sidecar with it first, then measure the STL
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here. Report that remediation instead of attempting raw STEP parsing.
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## Workflow
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1. Collect print intent: target process, material, layer height, and any
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machine or material datasheet the user can provide. If the process is
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unknown, measure once with the default 45° limit, then present findings
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per candidate process rather than guessing a single verdict.
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2. Read `references/process-limits.md` and select the limit column for the
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target process. A user-provided machine/material datasheet overrides the
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defaults; cite whichever source is used for every comparison.
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3. Run `measure` on the exact upload file. Do not inspect only a generator
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script, source CAD model, or console summary of the file.
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4. Run `orientations` when the process requires supports and the measured
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support area is nonzero. Report any candidate that materially reduces
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support area, with its build-height tradeoff.
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5. Compare each measured fact to the cited limit and report findings with
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restrained status labels:
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- `✅ pass`: the measured fact satisfies the cited limit.
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- `❌ fail`: a measured fact directly violates the cited limit.
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- `❓ need more info`: missing process context, unmeasured geometry,
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sampling too sparse to trust, or tool limitations.
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6. Order findings by severity: watertightness first (blocks slicing for
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every process), then wall thickness, then overhangs/supports, then
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orientation and cost signals.
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## Comparison
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Compare only trustworthy pairs of evidence.
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- Cite the limit source (process-limits table row, or the user's datasheet
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field) and the measured fact (JSON field path) for every finding.
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- Treat `p05_mm` below the wall-thickness limit as a violation even when
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`min_mm` alone could be a sampling outlier; report both values.
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- On an assembly, `wall_thickness` reports `body_count` and a `per_body`
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breakdown. Attribute a violation to the body it belongs to; a thin figure
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pooled across bodies is not a finding against the part as a whole.
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- Do not apply support-angle findings to powder processes (SLS, MJF); the
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relevant powder-process check is trapped-volume powder escape, which this
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tool does not yet measure — report that as `❓ need more info` when
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enclosed cavities are likely.
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- Do not silently rescale geometry. `scale.units_suspect` is measured from
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the bounding-box diagonal: when it is `true`, the source is probably in
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meters or inches, every down-facing face reads as resting on the plate, and
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overhang and support figures of 0.0 mean nothing. Report a unit/scale
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finding and ask the user to confirm units before comparing anything against
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a material limit.
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- Support-volume ratios are coarse upper bounds; report them as cost
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signals, not hard failures, unless the user has set an explicit budget.
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## Redesign Handoff
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For every `❌ fail`, include a concrete, plain-language redesign instruction
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with target numbers (for example "thicken the wall at [12.4, 3.0, 8.1] from
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0.6 mm to ≥1.2 mm" or "chamfer the overhang at [23.3, 10.0, 52.0] to ≥45°").
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When the `$cad` skill is installed, offer to apply the redesign instructions
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with it and re-measure the regenerated geometry here, repeating until no
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`❌ fail` findings remain. When `$cad-viewer` is installed, hand the measured
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file path(s) to it so the user can inspect the findings visually.
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