This interactive map visualizes New York census tracts on an orthographic projection, with a uniform grid of circles overlaid across the viewport. Grid points inside tract boundaries render as larger, colored circles using a sequential Cubehelix color scale, while points outside remain small. The code uses `d3.geoOrthographic`, `d3.geoPath`, and `topojson-client` for rendering, with `@turf/turf` for point-in-polygon tests and `rbush` for spatial indexing. Census data comes from a Gist, and drag and zoom interactions adjust rotation and scale.