Inspired by the City2Graph Python package (geospatial to
graph networks) and OSMnx by Geoff Boeing, I built a
Grasshopper C# script that visualizes the entire pipeline
as interactive 3D geometry.
WHAT IT SHOWS:
Layer 0: Street network as graph (perturbed grid, diagonal
streets, POI spatial join, mobility flow arcs, community colors)
Layer 1: Transit routes as GTFS-style colored pipes with stops
Layer 2: Cycle network as sparser green graph
Layer 3: All layers stacked in Z with vertical transfer pipes
EXTRAS:
- GNN message passing: slide from 0→20 iterations, watch
features diffuse through the network
(h_v = ReLU(MEAN(h_u : u in N(v)))) - Gravity model mobility flow with animated direction particles
- Community detection with boundary rings
- Full bake with teaching text, equations, legends, statistics
9 sliders. 620 lines. No plugins. Rhino 7/8.
Useful for anyone teaching urban computing, GIS-to-graph
pipelines, or spatial GNNs. The script IS the lecture.
available at www.wickersonstudios.com
— Michael Wickerson