CADmium: Fine-Tuning Code Language Models for Text-Driven Sequential CAD Design

TL;DR

CADmium leverages large language models fine-tuned on a new extensive CAD dataset to automate and accelerate the creation of 3D models from natural language descriptions, introducing novel metrics for structural quality assessment.

Contribution

This work introduces a large-scale CAD dataset with human-like descriptions and demonstrates fine-tuning code-LLMs for text-driven CAD generation, a novel application of LLMs in CAD design automation.

Findings

Effective generation of CAD sequences from natural language descriptions.

Introduction of geometric and topological metrics for quality assessment.

Significant speed-up in CAD design process.

Abstract

Computer-aided design (CAD) is the digital construction of 2D and 3D objects, and is central to a wide range of engineering and manufacturing applications like automobile and aviation. Despite its importance, CAD modeling remains largely a time-intensive, manual task. Recent works have attempted to automate this process with small transformer-based models and handcrafted CAD sequence representations. However, there has been little effort to leverage the potential of large language models (LLMs) for sequential CAD design. In this work, we introduce a new large-scale dataset of more than 170k CAD models annotated with high-quality, human-like descriptions generated with our pipeline based on GPT-4.1. Using this dataset, we fine-tune powerful code-LLMs to generate CAD sequences represented in a JSON-based format from natural language descriptions, demonstrating the viability and effectiveness of this approach for text-conditioned CAD generation. Because simple metrics often fail to reflect the quality of generated objects, we introduce geometric and topological metrics based on sphericity, mean curvature, and Euler characteristic to provide richer structural insights. Our experiments and ablation studies on both synthetic and human-annotated data demonstrate that CADmium is able to automate CAD design, drastically speeding up the design of new objects. The dataset, code, and fine-tuned models are available online.