Create technical illustrations from evidence

Teardown creates technical illustrations from physical objects, descriptions, photographs, CAD models, or concepts. It constructs geometry, inspects the rendered result, and packages a viewing page with coloring and download controls. The default deliverable includes a local preview and SVG, PNG, and PDF downloads unless a narrower output is requested.

The drawings explain construction or present an idea. They are not toleranced manufacturing drawings, and estimated dimensions remain estimates. A drawing intended for making a part belongs in the CAD tool's drawing workflow. Geometry and annotation correspondence are treated as exact; sheet proportions and line weights are recipes adjusted for the reference and reproduction size.

Use it for an authorized technical illustration, assembly explanation, external-shape view, section, or layered concept drawing. Supplied images are opened before reconstruction, and the depicted subject is distinguished from a reference that only demonstrates a finish.

A styling reference cannot establish another object's hidden construction or dimensions. Unknown internals are omitted, requested, or explicitly labeled illustrative. Fictional objects and abstract ideas are marked as concepts. Animation and simulation require a separate request.

The workflow does not claim visual verification from a successful file write. Rendering or browser limitations must remain visible in the handoff. Local model scripts require inspection and trust before execution because the bundled loader executes JavaScript and its Node vm is not a security sandbox.

Create an evidence.md record beside the drawing source. It classifies every feature group as supplied geometry or dimensions, photograph-derived estimates, hidden or unspecified construction, a fictional object, or an abstract concept. It also names intended use, output size, and commands for rebuilding and proofing.

Read the reference for projection, line hierarchy, density, annotations, and sheet furniture while excluding photographic skew, reflections, or paper discoloration. Collect silhouettes, component boundaries, fasteners, repeated features, and interfaces. Authoritative CAD or product drawings guide hidden features where available.

Choose the smallest explanatory view set. Assembly relationships suggest an exploded axonometric view with an assembled alternative. External shape may need one parallel view and a detail inset; specified dimensions suggest aligned orthographic views; internal passages suggest sections. Layered concepts become separated plates with color distinguishing parts.

The bundled viewer switches multi-part drawings between assembled and exploded views. Its annotation switch labels visible parts with names and leader lines. Balloons and dimensions require a separately requested annotated SVG sheet, with space allocated for views and labels.

Copy the provided assets and scripts into the project tooling area, excluding the skill's own test files. Define drawing.json and a model script through the documented model boundary. Derive all views and any parts list from one model. Bundled mesh helpers support hidden-line removal; existing CAD projection is preferred where a model is available or boolean cuts exceed those helpers.

Model the silhouette and major volumes first, then interfaces and fasteners, functional details, and occlusion. Detail must explain shape, manufacture, or assembly. Preserve known repeated counts and omit features too small to reproduce. Early proofing checks assembled and drawing states for floating contacts, blocked openings, misaligned holes, and correspondence across views.

The renderer applies line roles at paper size and can tint parts. Illustrative construction stays identified in the description with the concept flag enabled. Requested annotations must remain traceable to their features.

Render the actual deliverable, including fonts and background, and inspect parameter and spacing extremes. Correct the largest visible error, regenerate, and inspect both the changed region and whole composition. Troubleshooting addresses hidden-line leakage, overlapping explosion paths, weak part visibility, coarse curves, merged slots, crossed leaders, and incomplete fills. Scale claims require verified physical output or NTS labeling.

Package a standalone page that opens without a build step or running server. Test its controls and downloaded bytes so selected geometry, linework, and colors survive export. Deliver the preview, editable source, rendered image, drawing files, reconstruction assumptions, verified output size, and unresolved defects.

The bundled geometry helpers, renderer, viewer, and proof scripts form the main toolchain. CAD-projected SVG can enter through the model boundary. Typography, palette, accessible embedding, and surrounding layout remain owned by the corresponding better-* skills. Embedded third-party libraries and fonts require authorized acquisition and retained licenses; browser checks use a separate temporary headless profile.