LuaCAD

Scriptable CAD with Lua. Write parametric 2D and 3D models in Lua and export them to STL, 3MF, OBJ, PLY, or SCAD.

LuaCAD embeds Lua 5.4 in a Rust engine that evaluates CSG operations directly (via csgrs) or generates OpenSCAD code for external rendering.

Installation

From source

Requires Rust.

git clone https://github.com/ad-si/LuaCAD.git
cd LuaCAD
make install

This installs two binaries:

• luacad -- CLI for running and converting LuaCAD scripts
• luacad-studio -- GUI desktop app with live 3D preview

Usage

CLI

luacad convert model.lua output.stl          # Convert to STL
luacad convert model.lua output.3mf          # Convert to 3MF
luacad convert model.lua output.scad         # Export as OpenSCAD
luacad watch model.lua output.stl            # Rebuild on file changes
luacad convert model.lua out.stl --via-openscad  # Use OpenSCAD backend
luacad run model.lua                         # Execute (side-effects only)

Studio

luacad-studio

Desktop app with a code editor and 3D viewport. Edit Lua code on the right, see the model update on the left.

Example

my_cube = cube { size = { 1, 2, 3 } }

function my_sphere(radius)
  return sphere({ r = radius }):translate(5, 0, 0)
end

model = my_cube + my_sphere(2)

render(model)

Equivalent OpenSCAD:

module my_cube() {
  cube(size=[1,2,3]);
}

module my_sphere(radius) {
  translate([5,0,0]) sphere(r = radius);
}

union() {
  my_cube();
  my_sphere(2);
}

More examples in the examples/ directory.

Check out the website to see all supported features!

Why Lua?

The OpenSCAD language is limited and has several issues:

• Confusing functions vs modules
• Weird variable scoping
• Not a well establised programming language
  • Bad editor support
  • Limited documentation
  • Limited libraries
  • Bad error messages
  • Bad performance

Therefore, a real programming language should be used and it should ideally be interpreted and have good operator overloading support

• Julia - Too complex
• Python - Too slow and while easy to get started, hard to master

Lua is a better fit:

• Well-established, embeddable language
• Operator overloading for natural CSG syntax (a + b, a - b)
• Consistent semantics and good performance
• Similar syntax to OpenSCAD's language
• Already used in other CAD software (LibreCAD, Autodesk Netfabb)

Supported Export Formats

• SCAD
• 3MF
• STL
• DXF
• OBJ
• SVG
• WRL

Roadmap

• Full support for Belfry OpenSCAD Library v2
• Support for exporting .png files

Related

Other CAD software with programmatic model creation:

• BlocksCAD - Blockly-based CAD
• Flowscad - Rust interface to OpenSCAD
• FreeCAD - Python scripting
• HelloTriangle - 3D modeling with Python
• ImplicitCAD - Haskell-based CAD
• LibreCAD - Lua scripting
• Liquid CAD - 2D constraint-solving CAD
• ManifoldCAD - JavaScript-based online CAD
• OpenSCAD Rust - Rust OpenSCAD VM
• OpenSCAD - OpenSCAD language
• Rust Scad - Generate OpenSCAD from Rust
• scad_tree - Rust solid modeling via OpenSCAD
• ScalaCad - CSG in Scala
• SolidRS - Rust OpenSCAD model generation

History

The initial Lua implementation was done by Michael Lutz at thechillcode/Lua_CAD. The project was later rewritten in Rust.