AI & text-to-CAD
OpenSCAD
Definition
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.
Also known as: SCAD, .scad
Updated
Strengths and limits#
The OpenSCAD site describes it as software for creating solid 3D CAD models that focuses on CAD aspects rather than artistic modeling, and names CSG and extrusion of 2D outlines as its two main techniques. Parameters are ordinary variables, so a well-written script is easy to resize.
OpenSCAD's usual export formats are mesh formats such as STL and 3MF, not B-Rep STEP. That suits 3D printing but makes OpenSCAD output harder to take into mechanical CAD for further editing.
Sources
Related terms
CSG
CSG builds a shape by combining simple solids, such as cubes, cylinders, and spheres, with boolean union, difference, and intersection. OpenSCAD models are written this way, which makes them easy for people and language models to express as code.
CadQuery
CadQuery is an open-source Python library for building parametric CAD models in code on top of the Open CASCADE kernel. It can export STEP as well as STL and 3MF, which makes it a common target when LLMs are asked to write CAD scripts.
LLM
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.
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.