This example shows a modified Albers USA projection that adds Puerto Rico to the standard set of lower 48 states, Alaska, and Hawaii. The `albersUsaPr` function composes four separate conic projections—one for the contiguous United States, one each for Alaska and Hawaii, and a new one for Puerto Rico—and combines them into a single composite projection. A desktop perspective transform is applied on top, creating a subtle pseudo-3D “tilted map” effect where the vertical position dynamically scales horizontal coordinates. The visualization renders a world sphere, a 2°-step graticule, and the land mesh as SVG paths, demonstrating how custom projections can be composed in D3 v3 with streaming. The code includes the modified projection in `albers-usa-pr.js`, with the main page in `index.html`. It is forked from Mike Bostock’s block, licensed under GPL-3.0, and implemented with D3 v3.