FAST4-G(1)

📦
version 7.44.0 · 2 versions
, in nixpkgs unstable

💖 fast4-g(1) — the FASTGEN4 glow-up pipeline 💖

okay bestie, so this is the fast4-g page from the BRL-CAD manual set, and it's literally the tool that takes your crusty old FASTGEN 4.1 file and turns it into a gorgeous BRL-CAD geometry database. no cap, it's giving "glow-up montage" energy the whole way through. ✨

🦋 NAME 🦋

fast4-g — convert a FASTGEN4 file to a BRL-CAD geometry database. that's it. that's the whole job. and it slays at it. 💅

🌸 SYNOPSIS 🌸

fast4-g [-dwq] [-o plot_file] [-m muves_file] [-c id_list] [-C color_file] [-x RT_DEBUG_FLAG] [-b BU_DEBUG_FLAG] [-h] [-?] file.fastgen4 file.g

yes the flag soup is real but like, it's fine, we'll go through every single one together. 🫶

✨ DESCRIPTION ✨

so fast4-g converts a FASTGEN 4.1 format file (file.fastgen4) into a BRL-CAD geometry database (file.g). one file in, one glow-up out. iconic behavior honestly.

the supported FASTGEN element types and their BRL-CAD equivalents are:

  • CCONE1/CCONE2/CCONE3 → TRC
  • CHEX2 → ARB8
  • CLINE → cline
  • CQUAD/CTRI/CHEX1 → BOT faces
  • CSPHERE → SPH

each component gets built in either plate mode or volume mode — no, you don't get to pick per-vibe, that's just how it goes.

region ident numbers are computed as group * 1000 + component. yes, math. we love a little math. 🧮

object names come from $NAME elements, and if that's not forthcoming it falls back to generated comp_NNNN.r names — using an algorithm that ensures uniqueness, because two objects with the same name is a crime and we don't do crimes here. 💀

coordinates are read in inches and converted to millimeters. unit conversion, bestie. it's not a vibe, it's a necessity.

⚠️ important heads-up: for FASTGEN2 or FASTGEN3 files, convert them using rpatch(1) and then patch-g(1). do NOT just yeet them at fast4-g, that's not what she's for, she will simply not understand you. 😭

🎀 OPTIONS 🎀

  • -d — print debugging information. for when you're like "why is this doing that" and you need the lore.
  • -w — print warnings when a component is assigned a default (generated) name. basically a little "hey girl, this one got a placeholder name" notification. 🥺
  • -q — quiet mode; suppress progress output, emitting only error messages. for when you want zero small talk and only the bad news. 💅
  • -o plot_file — write all processed CTRI and CQUAD elements to plot_file in libplot3 format. the result can be viewed in mged(1) with the overlay command. cute for visualization besties. 🌈
  • -m muves_file — write CHGCOMP and CBACKING element information to muves_file as a MUVES input file. vintage-core. 🎞️
  • -c id_list — convert only the listed components. id_list is a comma-separated list of region idents and ranges, e.g. 3002,5678,1002-1100. picky and selective, we stan. 🔥
  • -C color_file — read region colors from color_file. each line holds five integers: low high r g b. aesthetic customization, literally the fun part. 🎨
  • -x RT_DEBUG_FLAG — set the librt debug flag to the given hexadecimal value. hex brainrot, respectfully. 🧠
  • -b BU_DEBUG_FLAG — set the libbu debug flag to the given hexadecimal value. same energy, different library. 💜
  • -h, -? — print a usage message and exit. the classic "help I'm lost" escape hatch. 🙈

⭐ EXAMPLES ⭐

Example 1. Convert a model and inspect it

fast4-g vehicle.fastgen4 vehicle.g
mged vehicle.g

converts the FASTGEN4 bulk data file into vehicle.g, then opens the result in mged(1) where the generated all group can be drawn. so you generate it, then you look at it. main character energy. 👑

Example 2. Convert selected components with a plot overlay

fast4-g -w -c 3002,5678,1002-1100 -o turret.plot3 vehicle.fastgen4 turret.g

processes only the listed component ident ranges, warns when default names are generated, and writes the converted CTRI and CQUAD facets to turret.plot3 for overlay display in mged(1). three vibes in one command, we love a multitasker. 🦋

💜 SEE ALSO 💜

brlcad(1), rpatch(1), patch-g(1), mged(1) — go read these too, they're in the friend group. 🫶

🌸 AUTHOR 🌸

BRL-CAD Team. legends, honestly.

This software is Copyright (c) 1994-2026 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

ngl if you find a bug, tell them. they're not gonna be mean about it. fr fr. 📬

okay that's the whole page bestie! this one's from the BRL-CAD manual collection, and you're reading the FAST4-G(1) page itself. go convert something gorgeous. 💖✨

📦 where this page comes from