LIBBG(3)

Link with -lbg.

The public interface is organized across the headers included by bg.h, including bg/chull.h, bg/clip.h, bg/lseg.h, bg/obr.h, bg/plane.h, bg/polygon.h, bg/sat.h, bg/spsr.h, bg/tri_pt.h, bg/tri_ray.h, bg/tri_tri.h, and bg/trimesh.h.

LIBBG is BRL-CAD’s geometry library, intended for generic computational geometry algorithms. Typical operations include point-in-polygon testing, line/sphere and triangle intersection tests, convex hull computation, oriented bounding box fitting, polygon triangulation (for example, ear clipping), surface reconstruction, and triangle mesh processing.

The library occupies a deliberate layer in the BRL-CAD stack. Algorithms in LIBBG do not require solid ray tracing of the BRL-CAD constructive solid geometry (CSG) boolean hierarchy; routines that need those high-level constructs belong in libanalyze instead, which uses librt to perform the necessary ray tracing. LIBBG is lower level and depends only on the numerics library (libbn) and the utility library (libbu). Strictly numerical algorithms that do not involve three-dimensional geometry concepts belong in libbn rather than here.

The complete API, including data structures and function signatures, is documented in the headers noted above and in the Doxygen-generated reference for the LIBBG module.

brlcad(1), libbn(3), libbu(3), libanalyze(3), librt(3)

The BRL-CAD Doxygen API reference provides the authoritative, up-to-date description of all public LIBBG routines.

BRL-CAD Team

This software is Copyright (c) 2015-2026 United States Government as represented by the U.S. Army Research Laboratory.

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