Tutorial 2: A geospatial flow map on a globe

Global refugee migration flows (UNHCR, 2000-2016): country nodes scaled by displaced population, connected by geodesic arcs on a textured globe, rendered in Cycles.

What you need: an edge list whose source/target columns are place names (countries or cities), ideally with a weight column for flow volume, or explicit latitude/longitude columns.

1. Import with geocoding

1. Open SciGraphs ▸ Data and load your file (File source, set the delimiter, Load File).
2. Map Source Nodes / Target Nodes and set the Weight Column to your flow volume. Enable Directed Graph if the flows are directional.

2. Configure the globe

1. Expand the Geospatial Options subpanel and enable it via its header checkbox.
2. Turn on Auto-Geocode Source/Target as Countries/Cities so the node names are resolved to coordinates via Nominatim. (Alternatively, disable geocoding and point the Latitude/Longitude fields at coordinate columns.)
3. Enable Show Earth Globe, set the Globe Radius and Globe Quality.
4. Choose a Globe Theme, e.g. NASA Blue Marble for satellite imagery, and tune the PBR Settings (water shine/roughness, land roughness, surface relief). Use Pre-download to cache the texture.
5. Set the Edge Style for the geodesic arcs.

3. Create the graph

Press Create Graph in Step 3, then Setup Visual in Step 4. The nodes are placed on the globe and edges are drawn as great-circle arcs.

Note

In geospatial mode the layout step is skipped automatically: positions come from coordinates, not from a layout algorithm.

4. Encode flow volume

1. In Visualization ▸ Appearance, drive node size from the weighted in-degree (total displaced population) using the attribute multiplier.
2. Color nodes or arcs by origin/destination class or by volume with a scientific colormap.

5. Render

Frame the globe with the camera, add the lighting rig (Scene Setup), and render with Cycles. Flow volumes and classifications stay on the graph as attributes, so restyling does not require reprojecting.