Had to vouch for your comment, for some reason it was not visible.
reply> Geometry is derived from OpenStreetMap (ODbL) and USGS 3DEP (public domain).
This is probably how I would have tackled this, saves on time, especially if Fable just writes code to convert OSM data to a reasonable ThreeJS model.
Do you have data on the tokens or $ cost of this?
replythis is a one-shot result but i have a really really lengthy prompt: https://github.com/PhiloLabs/fable51-worlds/blob/main/union-... with clear guidance in using subagents and self-QA loop.
reply~2 hour (extensive subagents usage), total ~8M tokens, ~$33 under API