REGIONS(nged)

🌸 REGIONS (nged) — the BRL-CAD User Commands era 🌸

okay so bestie, welcome to REGIONS(nged) 💖 this is a page from the BRL-CAD User Commands manual and it's literally about writing a region + Boolean member summary table out to a file. no cap, it's more useful than it sounds.

---

✨ NAME ✨

regions — write a region and Boolean member summary table to a file 🎀

---

🦋 SYNOPSIS 🦋

regions file object(s)

---

💅 DESCRIPTION 💅

so the regions command does a whole little journey through the hierarchy of one or more objects, and then writes a summary of all the regions it found to file. heads up though: the file gets opened in write mode and overwritten if it already exists 😭 so like, don't point it at your diary.

regions is one of four related commands that all share the same underlying logic but produce different levels of detail. group-chat lineup, get into formation 👑

• idents — region-level summary only: region count, ident, air code, material code, LOS, and path. no primitives listed. it's giving minimal.
• regions — region-level summary with the Boolean formula (member names and operators) for each region. that's us, hi 🫶
• solids — full summary all the way down to primitives: same as regions, plus the evaluated parameters of each primitive shape with accumulated transformation matrices applied. the overachiever of the group.
• tables — not a valid standalone command. invoking tables directly returns an input error 🙈 use one of the three specific commands above instead. it's the sibling who didn't show up.

💜 Output format 💜

the output file is a fixed-width text table. each region entry includes the following fields, in this exact order:

1. Region count — sequential index of the region as encountered.
2. Region ID (ident) — the region's identifier number.
3. Air code — air region code (0 if it's not an air region).
4. Material code (GIFTmater) — GIFT material code.
5. LOS — line-of-sight percentage (0–100).
6. Path — the full path from the listed object to the region.
7. Boolean members — the list of member primitives and Boolean operators (u, -, +) forming the region. combination sub-members are shown as RG entries; unknown object types show up as ??.

there's also a header written at the top of the file containing the command name, database filename, username, database title, units, and the list of objects processed 🌈

and after the table, a summary line gets appended:

Number Primitives = N
Number Regions = N

🧚 Primitive numbering 🧚

each primitive in the Boolean formula gets assigned a unique solid number in brackets (e.g. [3]). the same primitive used across multiple regions is assigned the same number if the accumulated transformation matrix is identical — a different transformation produces a different number. that uniqueness is tracked via a temporary file at /tmp/mged_discr 👀

---

🔥 EXAMPLES 🔥

⭐ Example 1. Write a regions summary for two groups

mged> regions regions_file group1 group2

writes a region and Boolean member summary for all regions reachable from group1 and group2 to regions_file. the result string reports how many primitives and regions were processed. slay.

⭐ Example 2. Write a summary for a specific top-level object

mged> regions hull_report.txt vehicle.c

writes the regions table for all regions under vehicle.c to hull_report.txt. iconic, honestly.

---

🌸 SEE ALSO 🌸

• idents(nged)
• solids(nged)

iykyk 💫

---

👑 AUTHOR 👑

BRL-CAD Team — legends, fr fr.

---

💀 BUG REPORTS 💀

reports of bugs or problems should be submitted via electronic mail to devs@brlcad.org 📧 (yes, actual email, very retro of them, we love it)

---

okay that's the whole page bestie, go forth and summarise those regions 💜 this was REGIONS(nged) from the BRL-CAD manual — version vibes courtesy of the BRL-CAD release, so check your local install for the exact date. mwah 🎀✨