AI & text-to-CAD
LLM
Large language model
Definition
An LLM is a large neural network trained on text to predict and generate language. In CAD, LLMs are used to write modeling code, drive a CAD program's API, answer software questions, or translate a prompt into structured modeling steps.
Also known as: large language model, language model
Updated
How LLMs reach geometry#
An LLM does not produce a solid by itself. It produces text, and that text becomes geometry through code or tools. The GPT-3 paper showed that large models can do new tasks from a few examples in the prompt, which is why they can write OpenSCAD, CadQuery, or CAD API scripts without special training.
Protocols such as MCP connect a model to a running CAD program, so it can issue commands and read results. Accuracy still depends on the model's spatial reasoning, which is weaker than its fluency with code, so generated dimensions and feature choices need checking.
Sources
Related terms
MCP
MCP is an open-source protocol for connecting AI applications to external tools, data, and workflows. In CAD it is used to let an LLM call a CAD program such as OpenSCAD, FreeCAD, or Fusion, run modeling commands, and read back results instead of generating geometry blind.
Text-to-CAD
Text-to-CAD is AI that turns a natural-language description into editable CAD geometry, such as a STEP file, a parametric model, or CAD code. The goal is a model with exact faces and dimensions that can be modified and manufactured, not just a shape that looks right on screen.
OpenSCAD
OpenSCAD is free, open-source CAD software where models are written as code using constructive solid geometry and extrusion of 2D outlines. Because the whole model is text, it is one of the easiest CAD targets for LLMs to generate and edit.
AI copilot
An AI copilot is an assistant built into CAD software that answers questions, suggests commands or best practices, and sometimes runs small tasks from a chat panel. Copilots help with the workflow around a model, and most do not generate a finished part from scratch.