D3 trials (fork of Cities on a Globe)
This interactive globe displays cities with populations over 100,000 as red circles, using an orthographic projection with drag-to-rotate and zoom capabilities. The visualization renders country boundaries from TopoJSON world-atlas data (110m resolution while dragging, 50m when stationary) and city locations from a CSV file, with circle sizes scaled by population. Tooltips show city names and populations via d3-tip. The implementation uses d3.geoOrthographic, d3.geoPath, d3.drag, and d3.zoom, filtering out cities on the hidden hemisphere based on their projected coordinates.