{"version":"1.0","type":"rich","title":"Faking building height by using polygon size","description":"This example visualizes building footprints from OpenStreetMap by faking height through polygon size rather than actual 3D extrusion. It shows how larger building footprints appear taller, using the SQL expression `st_area(the_geom_webmercator)/400` to compute a pseudo-height value from each polygon’s area. The code relies on PostGIS spatial functions (`st_area`, `the_geom_webmercator`) to transform the geometry and calculate the metric, then renders the result as a choropleth-like map where polygon size visually encodes the derived height. The data source is the `osm_export_polygon` table, and the approach emphasizes area-to-height mapping over true elevation data.","provider_name":"VizHub AI Studio","provider_url":"https://next.vizhub.com","html":"<iframe src=\"https://next.vizhub.com/viz/gist-4217947?mode=embed\" width=\"960\" height=\"500\" scrolling=\"no\" frameborder=\"1\"></iframe>","width":960,"height":500,"cache_age":3600}