solvecraft/docs/view-dxf.md

Export the current view as DXF

Choose File → Export Current View as DXF…, choose whether to omit hidden edges or export them as dashed lines, set Curve tolerance, then choose Export DXF… and a destination. Both settings are remembered. The Japanese menu is ファイル → 現在の表示をDXFでエクスポート….

On desktop, the export runs on a background worker while the window continues repainting and responding to its title-bar controls. A progress card shows mesh preparation, surface preparation, projection, hidden-line removal and writing, with a count and progress bar for the current stage. Cancel stops at the next mesh or traversal checkpoint; a single meshing call or sort may need to finish first. The model waits during the export and remains unchanged on success, failure and cancellation. Individual control-channel file.export_view_dxf commands use the same worker. The browser's export still runs synchronously on its single thread.

An export replaces its destination atomically only after the complete drawing is ready. Cancellation that takes effect before the final write preserves any previous file. Once that atomic write starts, it finishes; a late Cancel reports the completed save.

The drawing uses the camera when Export is pressed, including roll, the world's up axis and perspective. Only shown bodies are exported, at their current component/occurrence placements. Hidden bodies neither draw nor hide other bodies. The complete projected geometry is exported, including geometry beyond the viewport's edges. Grid, dimensions, constraints, selection highlights and other overlays are excluded. Turn off section analysis before exporting.

Sketches the viewport shows are exported too, so a design with only a sketch can be exported. Only profile curves are included: drawn curves, text outlines and drawn 3D-sketch curves; construction geometry, centerlines, projected references and points are not. Sketch curves go on their own SKETCH layer, each curve as one LINE or LWPOLYLINE (arcs, circles and splines as straight segments at the curve tolerance). Finished sketches are hidden behind bodies like body edges (dashed on HIDDEN when hidden edges are exported); the sketch being edited is drawn on top, as in the viewport. The export is refused only when there is neither a shown body nor a shown sketch curve.

Coordinates are 2D, Z=0, in millimetres. Orthographic views retain 1:1 dimensions in the view plane. Perspective views retain foreshortening, projected onto the plane through the camera target; they are intended for illustrations rather than dimensioned fabrication. Curves and curved silhouettes are approximated with straight segments at a default model-space chord tolerance of 0.01 mm. The setting accepts 0.0001–1 mm; smaller values produce finer curves and generally need more time and memory. This is not an exact analytic curve export or a tolerance guarantee for the original imported surfaces.

The AutoCAD 2000 ASCII DXF contains VISIBLE (continuous), SKETCH (when a sketch is shown) and, when requested, HIDDEN (2 mm dashes / 1 mm gaps) layers. Hidden curves use connected LWPOLYLINE entities with continuous linetype generation so the pattern does not restart on each chord. The pattern is embedded in the file. The polyline flags follow the Autodesk DXF reference.

Edges are split where another surface occludes them, including partial occlusion by another body. Hidden edges are never included in omit mode. Triangle diagonals and smooth seams are excluded; curved-body silhouettes are included. Very complex drawings fail with an error rather than returning an incomplete export. If geometry crosses the perspective camera's eye plane, zoom out before exporting.

Repeated component placements share their export mesh and triangle hierarchy. Each placement keeps its own edge choices, position and orientation; no bodies are fused or omitted to reduce the workload. A hierarchy over placed parts rejects unrelated occluders before searching a part's triangles. Already hidden intervals are skipped, and a fully hidden line stops searching. Desktop mesh preparation and independent line queries use at most eight computation workers; the browser runs serially. Export memory, candidate lines, output lines and total occlusion work remain bounded, and exceeding a budget returns an error without writing a partial drawing.

Programmatic callers use file.export_view_dxf with camera: Camera, hidden: "omit" or "dashed", optional tolerance (0.0001–1 mm) and optional path. Without path, the command returns the DXF text. The command does not modify the design or its undo history. The result also includes stats: placed body and shared mesh counts, source triangle count, retained mesh bytes, worker limit, candidate segment count, occlusion work, and preparation, projection and occlusion times in milliseconds. These timings exclude STEP import and DXF serialization; the worker limit is a maximum, not a claim that every worker was busy.