3D DXF Mesh object, created in Blender and imported into GRASS with v.in.dxf
screenshot: A. Bezzi, M. Neteler

GRASS: building footprints extruded to 3D blocks from 2D polygons with v.extrude
screenshot: M. Neteler
(data courtesy City of Trento, Italy - see "Mostra Strumenti Dati" for geodata download)

GRASS: building footprints extruded to 3D blocks, colorized by building type
screenshot: M. Neteler
(data courtesy City of Trento, Italy - see "Mostra Strumenti Dati" for geodata download)

Vector networks

Directions in vector networks drawn with d.vect
screenshot: M. Neteler

One way streets defined using backward/forward column attributes drawn with ps.map
screenshot: M. Neteler

Shortest path routing respecting one way streets drawn with d.path
screenshot: M. Neteler