A little web app to demonstrate (1) how to fetch 3D Tiles from the Google Photorealistic API and (2) how to correctly normalize & rotate the glTF tiles, or combine a set of them into one glTF that can be rendered in any standard engine.
NOTE: This is intended to be an educational tool to provide an easy way to experiment with the API and understand how to tweak different parameters like zoom & screen space error. See Google's Map Tiles API policies . Note especially that offline use is prohibited.
src/index.js uses loaders.gl to take a given lat/lng/zoom level, traverse the tileset and return a list of URLs to glTF tilessrc/Viewer.js takes these URLs, fetches them, normalizes the tiles from ECEF to centered around (0, 0, 0)See simple-node-example/ for a minimal example of just fetching tiles for a given region, which all the extra logic the app does around filtering for tiles that match the requested screen space error.
Think of it as roughly meaning "level of detail". The lowest possible SSE is 1 which is the highest quality. When you're zoomed out a lot you want to load higher SSE to get bigger tiles that cover a wider area (but that are lower quality).
Screen space error is a concept defined in the 3D Tiles specification, see: https://github.com/CesiumGS/3d-tiles/tree/main/specification#geometric-error
npm installnpm run dev