OFF-G(1)

off-g converts a model in Digital Equipment Corporation’s OFF (Object File Format) into a BRL-CAD database. It reads the OFF descriptor file file.off and writes a new BRL-CAD database database.g containing an NMG (n-Manifold Geometry) solid, a region that references it, and a top level identification record.

The descriptor file file.off is a small text header rather than the geometry itself. off-g parses two fields from it: a name field, whose value is used as the object title and to derive the generated s. (solid) and r. (region) object names, and a geometry field of the form geometry indexed_poly format geomfile. Only the indexed_poly data type is supported; the named geomfile is then opened relative to the current directory and read for the actual mesh.

The geometry file begins with a line giving the vertex, face, and edge counts, followed by one x y z coordinate triple per vertex and then one face per line listing an edge count followed by the 1-based vertex indices of that face. Per-face planes are fit and the faces are glued into a single NMG shell. See g-off(1) for the inverse conversion and mged(1) for working with the resulting database.

brlcad(1), g-off(1), mged(1), jack-g(1)

BRL-CAD Team

This software is Copyright (c) 1989-2026 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