CSG-G(1)

csg-g converts an OpenSCAD evaluated CSG file (file.csg) to a BRL-CAD file.g file. The CSG format is produced by running openscad -o file.csg input.scad and contains the fully evaluated CSG tree with all variables, modules, and loops resolved.

The converter preserves CSG structure, mapping OpenSCAD primitives and boolean operations directly to BRL-CAD equivalents rather than tessellating to mesh. Supported primitives include cube (RPP), sphere (SPH), cylinder (TGC), polyhedron (ARB or BOT), torus via rotate_extrude of circle (TOR), and extrusions of square, circle, and polygon profiles (RPP, TGC, or sketch+extrusion). Boolean operations (difference, union, intersection, group) and transformation matrices (multmatrix) are preserved. Colors are stored as object attributes. The import() node reads and inlines referenced STL files as BOT primitives.

Polyhedra are matched against ARB4, ARB5, and ARB8 when the vertex and face counts match and the shape is convex. Non-convex polyhedra and unmatched shapes fall back to BOT (bag of triangles).

The -d option prints debugging information during conversion.

g-scad(1), stl-g(1), openscad(1)

BRL-CAD Team

This software is Copyright (c) 2025 by the United States Government as represented by U.S. Army Research Laboratory.

Reports of bugs or problems should be submitted via electronic mail to devs@brlcad.org