What they did
The poster, u/keldareAI, is building a Roman city builder and had never been happy with the building and walker models. They gave Claude Fable 5.2 on high effort their existing systems and a short brief. No image-to-3D tool is involved: each agent writes a Python script for Blender that builds the model piece by piece in code. Each building gets its own agent in its own git worktree, working from a GitHub issue that names the building, its game files, where it appears in the campaign, a method document and a reference model to beat. The agent first writes a design in words with sizes, materials and its historical sources, plans the detail around the game's 54.8 degree camera, then builds, renders the exported file from fixed views, exports three levels of detail and captures them in the running game. A second agent reviews, the poster judges the in-game screenshots, and a separate integrator agent merges. An art director agent and a spec agent help write the issues.
How it went
After the first day the poster said they were finally satisfied with the results, after earlier models had always fallen short. In the first experiment the agent given only "a small temple of the Roman era", with nothing about the pipeline, produced the best model, which became the bar for every later building. Several agents are now building more models in parallel. Commenters praised the detail. The poster says three different routes reached the same quality and credits the method more than the tool.
Worth knowing
Historical accuracy is the model's own knowledge, checked by a second agent and the poster, not by a historian; where history and gameplay conflict, the agent asks. Each look loop takes minutes and there are many per building, and the poster tracks triangles, draw calls and materials per detail level to keep assets affordable. The post is in r/ClaudeCode and names the model, not the harness.