LuaCAD is a scripting library which uses OpenSCAD as engine to create 2D and 3D objects.

The LuaCAD library creates OpenSCAD code which is then used to create DXF, SVG, or STL files.

• Install OpenSCAD ( macOS, Linux, Windows )
• Install LuaJIT
  • macOS: brew install luajit
  • Ubuntu: sudo apt-get install luajit
  • Linux
  • Windows
• Download the project
• Unzip the project
• Change into the new directory: cd ./LuaCAD-main
• Create your <name>.lua model file (including a …:export("out.scad") line)
• Execute code with:

  bin/luacad <name>.lua

• Open the generated out.scad file with OpenSCAD

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);
}

LuaCAD:

require("luacad")

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)

model:export("simple.scad")

In comparison to OpenSCAD, LuaCAD provides several additional functions that make it easier to create complex models:

• 2D Objects
  • ellipse()
  • regular_polygon()
• 3D Objects
  • cone() (can use cylinder with different radii)
  • prism()
  • wedge()
  • torus()
  • surface()
• Extrusions
  • rotate_extrude() with angle parameter
• Mathematical/Programming
  • Most math functions (cross(), norm(), trigonometric functions)
  • List operations (len(), each, range())
• Special
  • import_3mf(), rands(), search()

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

… and the winner is Lua 🏆

• Powerful
• Consistent
• Fast
• Well established
• Easily embeddable and could therefore be directly integrated into OpenSCAD or a new CAD software
• Similar syntax to OpenSCAD language
• Already used in other CAD software like LibreCAD and Autodesk Netfabb

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

• Full support or Belfry OpenSCAD Library v2
• Support for exporting .png files
• Implement "LuaCAD Studio" GUI desktop app

Other CAD software that support programmatic creation of 3D models:

• BlocksCAD - Blockly-based CAD software
• FreeCAD - Python scripting
• ImplicitCAD - Haskell-based CAD software
• LibreCAD - Lua scripting
• Liquid CAD - 2D constraint-solving CAD for rapid prototyping
• ManifoldCAD - Online CAD software using JavaScript
• OpenSCAD Rust - Rust implementation of the OpenSCAD virtual machine
• OpenSCAD - OpenSCAD language

The initial work was done by Michael Lutz at thechillcode/Lua_CAD.