Show HN: Made an open-source Lego AI generator

LDRAW-NOVA is an open-source system that uses agentic large language models to design executable LEGO models in the LDraw assembly language. Running as a Dockerized web app (requires cloning ldraw-nova and ldraw-nova-docker at the same tag, building, and serving; HTTPS://localhost:8443 for VR or HTTP://localhost:8765 otherwise), it produces LDraw source (.mpd), Blender-editable glTF (.glb) with custom properties, rendered images, an interactive 3D/VR viewer, and the chat history/agent reasoning. Optional integration with Typesafe's Jev rerank API improves part- and model-searching; without it the system falls back to full-text search.

The core finding is that LLM agents generate more accurate geometry by writing Python “generator” code that performs the numeric math, rather than outputting geometry directly. To exploit that, the project supplies a Python tooling layer of primitives, examples and workflows: agents read instructions, plan (plan.json), emit generator scripts (generate.py) and iteratively render/inspect/adjust until they produce a finished model. Provided utilities include part discovery, collision/gap checks, headless rendering and example submodels. Current limitations: generation is computationally expensive and slow, relies on high-end models for large/correct builds, VR on Quest 3 has performance issues, and support for low-end agents and more model families (Technic, minifigs, manuals) needs improvement.