Mapheads out there will be pleased to read Avi Bar-Zeev’s multi-part series on How Google Earth (Really) Works. A graphics expert, Bar-Zeev is an original founder of Google Earth and created some of the rendering applications for Second Life and other VR simulators.
After the intro and legalese comes Part 1, The Result: Drawing a 3D Virtual Globe, which hashes out how Google Earth deals with map projection in free-perspective (vs. a fixed point of view, like in traditional maps) and the texture mapping required to bring that level of complexity to an average home computer. What I like about Bar-Zeev’s approach is that he really teaches the reader, as opposed to waving at the moving parts.
The next topic is how Google Earth streams data to the end user’s computer.