RPATCH(1)

📦
version 7.44.0 · 2 versions
, in nixpkgs unstable

💅 RPATCH(1) — the manual page, but make it make sense 🎀

okay so first things first: this is the manual page for rpatch, one of the BRL-CAD girlies, and I'm gonna walk you through it like we're texting at 1am. stay with me bestie, it's literally so much simpler than it looks. ✨

🌸 NAME 🌸

rpatch — reformat FASTGEN files for input to patch-g. that's it. that's the whole job. she's a pre-processor and she's iconic for it. 👑

🦋 SYNOPSIS 🦋

rpatch [-D] [-3] < fastgen_input_file > file.rp

read it, learn it, love it. stdin goes in, stdout comes out, no cap. 💫

💖 DESCRIPTION 💖

so rpatch is a pre-processor, right? her whole thing is reformatting FASTGEN target description files into the column-aligned record format that patch-g(1) expects — and patch-g(1) is the one that actually does the real conversion into a BRL-CAD geometry database. rpatch is basically the hype woman. she sets it up, patch-g knocks it down. 🫶

she reads a FASTGEN file from standard input and writes the reformatted records to standard output. no file arguments, no drama, just pipes. 😌

each input record gets parsed by fixed-width FORTRAN-style column fields — yes, FORTRAN-style, we love a retro moment — then the packed solid type code gets decomposed into separate type, thickness, and space-code values, and the whole thing gets re-emitted in the space-delimited layout that patch-g(1) reads. it's giving glow-up. it's giving transformation arc. 🔥

✨ OPTIONS ✨

  • -D — treat type 3 components as donuts rather than triangles. yes, donuts. no, I don't make the rules. 🍩
  • -3 — interpret the input as FASTGEN3 format, where the coordinate fields are each 10 columns wide. (the default layout uses narrower 8- and 9-column coordinate fields, so like... know which one you're feeding her, bestie.) 💅

🌈 EXAMPLES 🌈

Example 1. Convert a FASTGEN model into a BRL-CAD database

rpatch < model.fastgen > model.rp
patch-g -f model.rp model.g

The first command reformats the raw FASTGEN file into the intermediate .rp record format. The second feeds that file to patch-g(1) to produce the BRL-CAD geometry database model.g. two steps, one slay. ⭐

and listen — add -3 to the rpatch invocation when the source file is in FASTGEN3 format. don't forget, or she'll be confused and honestly same. 🙈

💀 DIAGNOSTICS 💀

the diagnostics are intended to be self-explanatory. that's literally the whole section. she trusts you. 🧚

👑 SEE ALSO 👑

brlcad(1), mged(1), patch-g(1) — go read those next, iykyk. 📚

🍓 AUTHOR 🍓

John R. Anderson. ty for your service, king. 🫡

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. found a bug? don't suffer in silence, tell the girlies. 📧

💖 and that's the whole page bestie — go pipe something into her and see the magic. periodt. 💖

okay bye ily, this page is from BRL-CAD and it's the RPATCH(1) manual — mwah, catch you in the next one 💅✨🎀

📦 where this page comes from