MKBUILDING(1)

NAME

mkbuilding - generate parametric buildings and building parts

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SYNOPSIS
DESCRIPTION
OPTIONS
EXAMPLES
SEE ALSO
AUTHOR
COPYRIGHT
BUG REPORTS

SYNOPSIS

mkbuilding [options] [output.g]

mkbuilding creates physically dimensioned BRL-CAD building geometry from archetype presets, a native JSON specification, OpenStreetMap (OSM) data, or OGC CityJSON 2.x data. Lengths are interpreted as metres unless the input schema declares another unit.

The generated model separates walls, slabs and foundations, roofs, opening frames and panels, structural columns and beams, and installations into material-bearing regions. Exterior walls use Boolean subtraction for doors, windows, and unfilled openings. Floor slabs, closed roof solids, and structural members use the requested physical thicknesses and cross sections. Building parts are generated recursively.

The native schema is JSON Schema draft 2020-12. It covers identity and classification; arbitrary or rectangular footprints; above- and below-ground storeys; skipped lower storeys; envelope dimensions and materials; roofs; doors, windows, and openings; column and beam grids; installations; nested building parts; OSM tags; CityGML attributes; and extension metadata. Print the schema with --schema. Example files are installed with the source under src/shapes/building/examples.

OSM GeoJSON Feature and FeatureCollection inputs accept Polygon geometry and either direct OSM properties or a nested tags object. Overpass JSON ways with inline geometry are also accepted. All tags are retained as osm::key database attributes. The Simple 3D Buildings tags for height, minimum height, storeys, minimum storey, material, colour, roof geometry, and building parts are interpreted. Documented building= taxonomy values select an appropriate physical archetype; unknown values are retained and use a conservative house-like realization.

CityJSON 2.x Building and BuildingPart objects are accepted. Classification, function, usage, roof type, measured height, storey counts and heights, children, transforms, extents, and referenced geometry bounds are mapped into the generator. Source attributes remain available as cityjson::key database attributes. CityJSON input is currently converted to a procedural building envelope derived from its bounds; its original boundary surfaces are not copied verbatim.

OPTIONS

-o file.g, --output file.g: Write the output database to file.g. The default is mkbuilding.g. A single positional output filename is accepted for compatibility.
-s file.json, --spec file.json: Read a native JSON, OSM GeoJSON, Overpass JSON, or CityJSON specification.
-p name, --preset name: Start from house, apartments, office, warehouse, church, barn, garage, parking, greenhouse, sports_hall, silo, tower, civic, carport, shed, or service. An OSM building= value may also be used.
-t value, --type value: Set the OSM-compatible building type stored on the generated object.
-n name, --name name: Set the top-level object name.
-L count, --levels count: Set the number of above-ground storeys.
-W metres, --width metres: Set the rectangular footprint width. Must be used with --depth.
-D metres, --depth metres: Set the rectangular footprint depth. Must be used with --width.
-H metres, --floor-height metres: Set a uniform floor-to-floor height.
-R shape, --roof-shape shape: Set an OSM-compatible roof:shape. Use --list-roofs to show the implemented values.
--roof-height metres: Set roof height above the facade.
--wall-thickness metres: Set exterior wall thickness.
--structure system: Enable a structural column-and-beam grid and record its system name.
--no-auto-openings: Suppress automatically placed exterior doors and windows.
-f, --force: Replace an existing output database.
-j, --append: Append generated objects to an existing database.
--validate-only: Parse, normalize, and validate the input without writing geometry.
--effective-spec file.json: Write the fully resolved native specification after imports and command-line overrides.
--demo-file file.g: Generate a catalog containing at least 50 distinct building types and a nested building-part example. Generation fails if two catalog entries differ only in classification or appearance but have identical shape and structure.
--schema: Print the native JSON Schema and exit.
--list-types: List the covered OSM building taxonomy and exit.
--list-roofs: List supported OSM roof shapes and exit.
-h, -?, --help: Print usage information and exit.

EXAMPLES

Example 1. Generate a three-storey framed house

mkbuilding --preset house --levels 3 --structure wood_frame -o house.g

Example 2. Validate and generate an OSM GeoJSON building

mkbuilding --validate-only --spec building.geojson
mkbuilding --spec building.geojson -o building.g

Example 3. Generate a broad taxonomy catalog

mkbuilding --demo-file buildings.g