IGES-G(1)

📦
version 7.44.0 · 2 versions
, in nixpkgs unstable

🎀 IGES-G(1) — a BRL-CAD moment 🎀

okay so bestie, this is the IGES-G(1) page from the BRL-CAD manual set, and we're about to make file conversion actually make sense. buckle up 💖

✨ NAME ✨

iges-g — convert an IGES file to a BRL-CAD database. literally what it says on the tin, no cap 🫶

🌸 SYNOPSIS 🌸

iges-g [-3] [-d] [-n] [-t] [-p] [-N solid_name] [-x rt_debug_flag] [-X nmg_debug_flag] -o database.g file.iges

🦋 DESCRIPTION 🦋

iges-g reads an IGES (Initial Graphics Exchange Specification) file and writes the converted geometry straight into a BRL-CAD database.g file. and like, the input is expected to conform to IGES version 5.1 — that's the vibe check it's holding you to 👑

So if you pass none of -3, -d, -n, or -t, the default action is lowkey iconic: it converts only IGES solid model entities — that's CSG primitives and planar-face BREP objects — into their BRL-CAD equivalents. Most CSG conversions are exact, but heads up bestie: solids of revolution get approximated by a series of BRL-CAD cones, and solids of linear extrusion get approximated by polysolids. not exact, but it's giving "close enough" 💅

Planar-faced BREP objects are written as BOT solids by default (or as NMG solids if you say -p). slay.

The -3/-d, -n, and -t options are mutually exclusive — pick one, don't be messy 🙈 — and they select alternate conversion modes: drawings, B-spline surfaces, or trimmed surfaces, respectively. The -o output option is required, fr fr, no output no party.

when the chosen mode can't represent something that's actually in the file, iges-g prints suggestions for the options that would convert the remaining entities. so it's not ghosting you, it's helping ✨

And if you wanna export geometry in the other direction? see g-iges(1). we love a bidirectional moment 🌈

💅 OPTIONS 💅

  • -3 — Convert IGES drawings to BRL-CAD NMG objects without the final projection into 2D, preserving 3D drawings produced from a 3D model. Solid model entities are ignored. 👀
  • -d — Convert IGES drawings to BRL-CAD NMG objects (projected to 2D). Solid model entities are ignored.
  • -n — Combine all rational B-spline surfaces in the IGES file into a single BRL-CAD spline solid. one solid, main character energy ⭐
  • -t — Convert all trimmed surfaces in the IGES file into a single BRL-CAD NMG trimmed-NURBS solid.
  • -p — Write BREP objects as NMG solids instead of the default BOT solids. glow-up mode ✨
  • -o database.g — Specify the output BRL-CAD database file. This option is required. 🚨
  • -N solid_name — Name the single solid created by the -n or -t option. If not given, the default name "all" (or a unique variant) is used. Ignored for all other modes. 🏷️
  • -x rt_debug_flag — Set the librt debug flag, given as a hexadecimal value. See raytrace.h for the bit definitions. 🔍
  • -X nmg_debug_flag — Set the NMG routine debug flag, given as a hexadecimal value. See nmg.h for the bit definitions.

🔥 EXAMPLES 🔥

Example 1. Convert IGES solid geometry and inspect the result

iges-g -o widget.g widget.iges
mged widget.g 'tops'

Convert the CSG and planar-face BREP entities of widget.iges into widget.g, then list the resulting top-level objects with mged(1) to verify the conversion. literally the "did it work" ritual, we love her 🎀

Example 2. Convert trimmed surfaces into a single named solid

iges-g -t -N hull -o boat.g boat.iges

Collapse all trimmed surfaces in boat.iges into one BRL-CAD NMG solid named "hull" inside boat.g — useful for surface models that have no CSG geometry. it ate, no crumbs 💀

👑 SEE ALSO 👑

brlcad(1), g-iges(1), mged(1)

The Initial Graphics Exchange Specification (IGES) Version 5.1, IGES/PDES Organization, September 1991. 📚

🧚 AUTHOR 🧚

BRL-CAD Team 💜

This software is Copyright (c) 1991-2026 by the United States Government as represented by U.S. Army Research Laboratory.

🍓 BUG REPORTS 🍓

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

don't suffer in silence bestie, tell the devs 🫶

okay that's the whole page!! this gorgeous little number lives in the BRL-CAD manual collection and is page IGES-G(1) of that set — mwah, go convert something iconic 💖✨

📦 where this page comes from