glTF (GL Transmission Format)

glTF 2.0 is the Khronos Group's open standard for delivering three-dimensional scenes: geometry, materials and scene structure are described in JSON, while vertices and faces live in binary buffers. The format was conceived as the JPEG of 3D, and today browser engines, game editors and viewers read it without conversion.

OpenStreetMap maps are exported to glTF when you need a city with volume rather than a picture: to spin a block right in the browser, drop the built-up area into a Unity or Unreal scene, show the surroundings in AR, or assemble the geometric base of a digital twin. From there the model is edited in Blender like any other 3D scene.

The file contains the buildings of the selected area: each house outline is extruded upward to its height from the height and building:levels tags, and when those are missing a sensible value is substituted by building type — a detached house gets about six meters, a garage three, a building with no stated type nine, roughly three floors. Roads, water and greenery do not make it into the 3D scene. Where elevation data (DEM) covers the area, the buildings sit on the terrain and the base plane under the model follows the slope. Color is assigned by building type, the material is matte, with no metallic sheen.

Coordinates are converted to local meters with the origin at the center of the area, so the model arrives at real-world scale and right next to the scene origin — no hunting for it and no rescaling. The .gltf file is self-contained: the binary buffers are embedded inside as data URIs, no separate .bin appears alongside. If you need a single compact binary, GLB sits right next to it.