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name: technical-illustration description: Use when the user needs an explanatory technical figure showing parts, assemblies, operation, dimensions, callouts, or a controlled visual sequence.

Technical illustration

Select it when

Choose this skill for an explanatory figure whose meaning depends on physical appearance, exploded relationships, section views, callouts, or a sequence of operation. Use it for manuals, training, proposals, and engineering communication. Do not use it for a pure graph, formal schematic, manufacturing drawing, or photorealistic product render unless that is explicitly the requested deliverable.

Story and modeling

State the reader's question and the viewing convention: identify parts, show assembly order, explain motion/flow, expose an internal section, or compare states. Establish a datum/orientation, part IDs, leader-line targets, scale status, and what is intentionally omitted. Separate measured dimensions from illustrative proportions. If geometry or safety depends on exact values, link to the controlled CAD/drawing source.

The output is an explanatory depiction, not automatically a standards-compliant technical product definition. A generic diagram renderer cannot guarantee projection rules, tolerances, datum systems, material hatching, or manufacturing authority.

Styling and customization

Use a restrained palette, high-contrast labels, consistent line weights, and uncluttered leader lines. Use exploded offsets and transparency sparingly; preserve occlusion cues and assembly order. Number parts consistently and provide a keyed parts list. Use section hatching or dimension marks only when their convention is explained. Avoid decorative perspective that changes the apparent relationship or hides a critical interface.

Renderer routing

Preserve a renderer explicitly requested by the user. Use pikchr or tikz for controlled geometry, diagramsnet or excalidraw for manually composed callouts and assembly views, and ditaa, goat, or svgbob for text-native sketches. Use d2, graphviz, or plantuml when the illustration is really a relationship abstraction. No listed renderer is a CAD, geometric-dimensioning, or photorealistic illustration engine; offer an integration gap rather than faking precision.

Review

Check callout target accuracy, part numbering, orientation, section/hidden-line conventions, label legibility, contrast, and print behavior. Confirm that dimensions have units and that “not to scale” is visible where applicable. Have a domain reviewer verify the physical interpretation and compare against the controlled source. Record revision and intended audience.

References

  • ISO 128-1:2020 — general principles for technical drawings; consult the applicable part and licensed text for production work.
  • ISO 5455:1979 — scales for technical drawings; a renderer does not enforce scale.
  • ISO 5457:1999 — sizes and layout of drawing sheets; page-layout integration may be needed.
  • IEC 61082-1 — electrotechnical documentation conventions where the illustration is part of such a document.

Integration opportunities

Standards-aware projection, dimensioning, tolerancing, CAD import, vector authoring, material/section conventions, and controlled title-block export are not provided by the current diagram renderers. Treat those as integration opportunities when exact engineering documentation is required.