Drawings & export

Project and export BREP geometry to DXF R12 drawings. The dxf-export verb performs hidden-line-removed orthographic projection along a view direction; drawing-export composes a complete ISO 128-30 multi-view technical drawing with title block, sections, dimensions, and GD&T annotations.

Entries

dxf-export · drawing-export

`dxf-export`

Project a shape along a view direction and write DXF R12.

Input — flag-form only (positional input.brep output.dxf [--view x,y,z] [--deflection D]).

Parameters

name	type	required	description
`--view`	`x,y,z`	no	View direction for orthographic projection (default `0,0,1` = top-down along +Z)
`--deflection`	double	no	Tessellation deflection for wire/edge rendering (default `0.1` mm)

Returns — A JSON envelope with output (file path), view (the direction used as [x, y, z]), and deflection. The DXF R12 file is written using hidden-line-removed projection.

Example

occtkit dxf-export bracket.brep bracket.dxf --view 0,0,1 --deflection 0.05

{
  "output": "bracket.dxf",
  "view": [0, 0, 1],
  "deflection": 0.05
}

Drives — OCCTSwift.Exporter.writeDXF(shape:to:viewDirection:deflection:) (v0.138+).

Notes — Wraps hidden-line-removed projection; useful for single orthogonal views or quick exports. For multi-view technical drawings with sections and annotations, use drawing-export.

`drawing-export`

Compose a complete ISO 128-30 multi-view technical drawing with border, title block, projection symbol, sections, dimensions, and GD&T annotations. Output is DXF R12.

Input — JSON spec on stdin or file path argument. The spec has optional shape (path to input BREP, required by CLI but omitted by in-process callers) and output (required by CLI; in-process callers return a DrawingComposerResult instead). All other fields drive the drawing layout and annotation.

Parameters — See DrawingSpec schema for full field definitions. Key top-level fields:

name	type	required	description
`shape`	string	yes (CLI)	Path to input BREP file
`output`	string	yes (CLI)	Path for output DXF R12 file
`sheet`	object	yes	Paper size, orientation (`landscape`\|`portrait`), projection angle (`first`\|`third`), scale (`"auto"` or `"N:D"`), border toggle, projection-symbol toggle
`title`	object	no	Title-block metadata: `title`, `drawingNumber`, `owner`, `creator`, `approver`, `documentType`, `dateOfIssue`, `revision`, `sheetNumber`, `language`, `material`, `weight`
`views`	array	yes	List of orthographic views, each with `name` and optional custom `direction` (default ISO standard directions)
`sections`	array	no	Cross-section views, each specifying `name`, `plane` (origin + normal), and optional `hatchAngle`, `hatchSpacing`, `viewDirection`
`centerlines`	enum	no	`"auto"` (default) or `"none"` — auto-generate revolution axes
`centermarks`	mixed	no	`"auto"`, `"none"`, or an explicit array of `{view, x, y, extent?}` for circular features
`cosmeticThreads`	array	no	ISO 6410 thread overlays: `{view, axisStart, axisEnd, majorDiameter, pitch, callout?}`
`surfaceFinish`	array	no	ISO 1302 surface-finish symbols: `{view, position, leaderTo, ra, symbol?, method?}`
`gdt`	array	no	ISO 1101 GD&T feature-control frames: `{view, position, symbol, tolerance, datums?, leaderTo?}`
`detailViews`	array	no	Zoomed close-ups: `{name, fromView, centre, radius, scale, placement?}`
`dimensions`	array	no	Explicit dimensions: `{view, type, from?, to?, offset?, ...}` per `DimensionKind` (`linear`\|`radial`\|`diameter`\|`angular`)
`deflection`	double	no	Tessellation deflection (default `0.1` mm)

Returns — A JSON envelope with output (DXF path), sheet (paper size + orientation), projection (first- or third-angle), scale (readable label), viewCount, sectionCount, detailCount. The DXF R12 file contains the complete drawing: ISO 5457 border, ISO 7200 title block, ISO 5456-2 projection symbol (if enabled), HLR orthographic views, auto-hatched sections, cutting-plane lines, auto-centerlines, auto-centermarks, cosmetic threads, surface-finish symbols, GD&T frames, and detail callouts.

Example

cat > drawing.json <<'EOF'
{
  "shape": "shaft.brep",
  "output": "shaft_drawing.dxf",
  "sheet": {
    "size": "a3",
    "orientation": "landscape",
    "projection": "third",
    "scale": "1:2"
  },
  "title": {
    "title": "Drive Shaft Assembly",
    "drawingNumber": "DRV-001-A",
    "material": "Steel 1045",
    "revision": "1"
  },
  "views": [
    {"name": "front"},
    {"name": "top"},
    {"name": "right"}
  ],
  "centerlines": "auto",
  "centermarks": "auto"
}
EOF

drawing-export drawing.json

{
  "output": "shaft_drawing.dxf",
  "sheet": "A3 landscape",
  "projection": "third",
  "scale": "1:2",
  "viewCount": 3,
  "sectionCount": 0,
  "detailCount": 0
}

Drives — DrawingComposer.Composer.render(spec:shape:) and downstream OCCTSwift ISO primitives: Sheet.render (border + title block + projection symbol), Drawing.project (per-view HLR), Drawing.transformed + Drawing.bounds (layout and autoscale), Shape.section2DView (hatched sections), Drawing.addCuttingPlaneLine, Drawing.addAutoCentrelines / addAutoCentermarks (ISO 128-40), DrawingAnnotation.cosmeticThreadSide (ISO 6410), .surfaceFinish (ISO 1302), .featureControlFrame (ISO 1101), Drawing.detailView, and DrawingScale.preferred (ISO 5455 standard scales).

Notes — In-process callers (import DrawingComposer) call Composer.render(spec:shape:) directly; the CLI wrapper exists only to serve JSON-driven consumers (OCCTMCP, Python pipelines). The spec’s shape and output fields are only used by the CLI. Section hatching angle and spacing default to π/4 radians (45°) and 3 mm. The ISO projection symbol is drawn only when sheet.projectionSymbol is true (omitted or null defaults to true for A1–A4; A0 defaults to false). For sub-entity highlighting or enrichment (e.g. face plane keys for coplanar relationships), use the in-process API with a custom ShapeEnricher; the CLI surface does not expose that hook.