LuaCAD: Parametric CAD Scripting Tool Using Lua and Rust

Introduction to LuaCAD

LuaCAD is a new tool for parametric computer-aided design (CAD) that allows users to create 2D and 3D models by writing scripts in the Lua programming language. This approach provides a programmatic way to define geometric shapes and structures, offering precise control over model parameters.

Technical Architecture and Features

The system embeds Lua 5.4 within a Rust engine, which handles constructive solid geometry (CSG) operations directly via the Manifold library or generates OpenSCAD code for external rendering. LuaCAD supports exporting models to multiple formats including 3MF, STL, OBJ, PLY, OFF, AMF, and SCAD, and can also render models directly to PNG images. It includes features like operator overloading for natural CSG syntax, similar to other CAD software.

LuaCAD offers both a command-line interface (CLI) for script execution and conversion, and a graphical user interface (GUI) desktop application, LuaCAD Studio, which provides a live 3D preview of models. The tool also supports the Belfry OpenSCAD Library v2 (BOSL2) through a reimplementation within LuaCAD, allowing rendering and export without requiring OpenSCAD or BOSL2 installations.

Comparison with OpenSCAD

LuaCAD positions itself as an alternative to OpenSCAD, highlighting Lua's advantages such as more power, consistency, and speed compared to OpenSCAD's scripting language. Lua's embeddability is also noted as a benefit. The project provides examples demonstrating how LuaCAD's syntax for defining models compares to equivalent OpenSCAD code, showing a more concise structure.

Installation and Usage

Users can install LuaCAD via Cargo for both the CLI (`luacad`) and the GUI (`luacad-studio`). Building from source requires Rust, a C++ compiler, and CMake. The CLI supports various commands for converting models, watching files for changes, rendering to PNG, printing model information, linting scripts, and executing scripts. The `convert` and `watch` commands infer output formats from file extensions, with options to override or use an installed OpenSCAD binary for export.