LegoGPT Can Now Design 3D Structures That Actually Work

A team of researchers has introduced LegoGPT, an open-source AI model capable of generating stable 3D Lego structures. This breakthrough demonstrates how AI can design physical objects that comply with real-world physics.
Stability Meets Creativity in AI-Generated Lego Designs
According to researchers at Carnegie Mellon University, LegoGPT can turn text prompts into buildable Lego structures. The model doesn’t just imagine shapes—it ensures they can actually stand upright without falling apart.
Users can request creative designs like a “streamline elongated vessel” or a “backless bench with armrest.” In response, the model generates accurate, stable structures that meet those criteria. The best part? It’s available on GitHub under the permissive MIT license, making it accessible for developers and educators alike.
This is made possible by two main components: a fine-tuned AI model and a powerful stability checker. LegoGPT uses a customized version of LLaMA-3.2-Instruct with one billion parameters. That’s paired with Gurobi, a mathematical solver that runs stability analysis on each structure.
Backed by Data and Real-World Testing
The team didn’t stop at just generating digital designs. They also built StableText2Lego—a dataset of over 47,000 structures featuring more than 28,000 unique objects. Each entry comes with code, 3D models, and rich captions. This dataset helped train LegoGPT to generate realistic, functional builds.
What’s more impressive is how the team tested the results. Using a dual-robot system, researchers built and evaluated the AI-generated designs. They also asked human builders to recreate some of them. Whether built by robots or humans, the results were nearly flawless. According to the research paper, 99.8% of the models passed the stability test.
A New Direction for AI and Engineering
LegoGPT is not just a toy or design tool—it’s a step toward AI models that understand and respect physical constraints. By generating structures that can exist in the real world, it bridges a gap between virtual intelligence and practical engineering.
This project could be a game-changer for education, architecture, robotics, and even product design.