v.build(1)

📦
version 8.4.2 · 8 versions
, in fedora 44

💖 v.build 💖

okay bestie, so this is v.build(1) from the GRASS GIS User's Manual — it's the lil module that makes topology happen for vector maps, and yes it can also sniff out topological errors for you. slay. 🌸

✨ NAME ✨

v.build — creates topology for vector map. and optionally?? also checks for topological errors. multitasking queen 👑

🏷️ KEYWORDS 🏷️

vector, topology, geometry

🎀 SYNOPSIS 🎀

v.build
v.build --help
v.build [-e] map=name  [error=name]  option=string[,string,...]
[--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]

🚩 Flags 🚩

  • -e — Extensive checks for topological errors. like it goes deep bestie, performing in-depth checks for topological errors while building topology 🔍
  • --overwrite — Allow output files to overwrite existing files. no hesitation, just vibes 💅
  • --help — Print usage summary
  • --verbose — Verbose module output. it will NOT stop yapping (affectionate)
  • --quiet — Quiet module output
  • --ui — Force launching GUI dialog

🧸 Parameters 🧸

  • map=name [required] — Name of vector map
  • error=name — Name for output vector map where erroneous vector features are written to
  • option=string[,string,...] [required] — Build topology or dump topology or indices to standard output
    • Options: build, dump, sdump, cdump, fdump
    • Default: build
    • build: build topology
    • dump: write topology to stdout
    • sdump: write spatial index to stdout
    • cdump: write category index to stdout
    • fdump: write feature index to stdout (OGR simple-feature-based formats only)

🌈 DESCRIPTION 🌈

so v.build builds support files for GRASS vector maps. those support files are the ones supplying topology and category information, spatial index included, and other GRASS modules literally need them to function. main character infrastructure fr fr 🫶

GRASS is out here generating these support files automatically — it's giving self-sufficient. only in rare cases does the user have to (re)build them.

if you want the whole lore, refer to vector data processing in GRASS GIS for more info on the GRASS vector data model. ✨

💅 NOTES 💅

v.build creates support files only for vector maps located in the user's current mapset. periodt. it's not possible to rebuild support files (option=build) for vector maps from other mapsets. stay in your lane bestie 😭

in case of errors, you can optionally generate an error vector map containing the erroneous vectors for later inspection. iconique.

if error vector map is specified, v.build checks:

  • isolated bondaries (which are not forming any areas),
  • centroids outside of area,
  • duplicated centroids.

Extensive checks for topological errors (flag -e) also includes:

  • lines or boundaries of zero length,
  • intersecting boundaries, ie. overlapping areas,
  • areas without centroids that are not isles.
⚠️ ngl that's a lot of checks. use the flag when you want the full forensic analysis, not just the vibe check.

🍓 EXAMPLES 🍓

🛠️ Build topology

Note that option=build recreates also spatial and category indices, not only topology. For linked OGR layers (see v.external) also feature index is created.

v.build map=urbanarea option=build

Note that the vector map urbanarea must be located in the current mapset.

📤 Dump topology or indices

Dump options print topology, spatial, category or feature index to standard output. Such information can be printed also for vector maps from other mapsets. A description of the vector topology is available in the GRASS GIS 8 Programmer's Manual, section "Vector library topology management".

v.build map=urbanarea option=dump

👀 SEE ALSO 👀

  • v.build.all
  • v.build.polylines
  • v.edit
  • v.split
  • v.support

See also wxGUI vector digitizer.

👑 AUTHORS 👑

Dave Gerdes, U.S.Army Construction Engineering Research Laboratory, Michael Higgins, U.S.Army Construction Engineering Research Laboratory, Radim Blazek, ITC-irst, Trento, Italy

💾 SOURCE CODE 💾

Available at: v.build source code (history)

Accessed: Saturday Jan 17 05:41:18 2026

Main index | Vector index | Topics index | Keywords index | Graphical index | Full index

© 2003-2025 GRASS Development Team, GRASS GIS 8.4.2 Reference Manual

okay that's the whole page bestie, no cap, every last flag accounted for 🧚✨ and btw — this was all served up by GRASS 8.4.2, and it's literally titled v.build(1). go build some topology, you absolute legend 💜🦋

📦 where this page comes from