OSMnx · Elevation, DEM & 3D terrain (La Paz)
Build a 3D urban terrain for Avenida Naciones Unidas, La Paz within a 2 km radius. La Paz’s dramatic relief makes the DEM pipeline, node elevations and street grades clearly visible.
This walkthrough mirrors the Elevation panel.
Before you begin
- Open the OSMnx tab and ensure Blender has internet access.
- An OpenTopography API key gives the best DEM quality; Open-Elevation works without one. A local GeoTIFF is also supported.
1. Download the area (2 km radius)
In Download, set Download Method to Point (or Address), enter the location near Avenida Naciones Unidas, La Paz, set Distance to 2000 m, and press Download Graph. Then Project Graph in Graph Operations.

2. Get elevation data
Expand Elevation. In Get Elevation:
- DEM Source: OpenTopography, Open-Elevation, or Local GeoTIFF (set Local Path).
- Enable Apply to Nodes and Create Terrain.
- Set the Vertical Scale and, for API sources, the API Resolution and Workers.
Press Get Elevation. Node elevations are fetched and a terrain mesh is built under the network.

For a local DEM, set DEM Source to Local GeoTIFF and the Local Path. Use Export AOI to write the area of interest for downloading a Copernicus DEM tile.
3. Apply 3D positions
Press Apply 3D Positions so the network conforms to the terrain surface, draping the streets across the slopes.

4. Add edge grades
Press Add Edge Grades to compute each edge’s slope (grade) and its absolute value (grade_abs). The steep streets of La Paz produce high grades.

5. Elevation-aware routing
Open Routing, set Path Weight to elevation_impedance and choose an Alpha. The cost becomes length * (1 + alpha * |grade|), so steep climbs are penalized and flatter detours win. Compare against a plain length route to see the difference.

6. Add a basemap
In Step 5 — Basemap Texture, choose a Source — the dropdown is grouped by provider (Esri, OpenStreetMap, CARTO, Mapbox, MapTiler, Stadia/Stamen) plus a custom WMS option, each exposing several styles — and a Zoom, then Fetch & Apply to drape satellite or map imagery over the terrain.

For the full basemap workflow — comparing imagery sources, WMS layers and tuning zoom — continue with Basemaps & API textures, which reuses this same La Paz terrain.
Next steps
Continue with Basemaps & API textures to drape imagery from the mapping APIs over this terrain, then move on to the City2Graph tab with Import urban data.