No it does not. Computing the spherical polygons that make up the Voronoi diagram just happens once.<p>The expensive part is rendering them in an arbitrary map projection.<p>Considering this is an orthographic projection, and therefore spherical polygon edges are all ellipses, rendering this picture could certainly be special-cased to only draw ellipses and thereby run much faster. But it’s using a very general D3-geo framework. If you want you can easily tweak the code and the map will be drawn on whatever projection you like.<p>To see some of the possibilities, go to <a href="http:&#x2F;&#x2F;bl.ocks.org&#x2F;mbostock" rel="nofollow">http:&#x2F;&#x2F;bl.ocks.org&#x2F;mbostock</a> and scroll down a bit.