LoftyCAD: Sketch, Render, Slice and Print.

Free CSG CAD for 3D printers for Windows. It came out of dissatisfactions with SketchUp, and with free 3D CAD programs in general. However, it has since grown into something a lot bigger.

LoftyCAD philosophy and goals

General

LoftyCAD is a hierarchical CSG 3D-modelling program. It is open-source, actively maintained, and free to all. Simple to use like Sketchup, but with some improvements: In particular, it will:

• Retain the identity of 3D shapes, and not merge shapes irreversibly with others
• Produce a single triangle mesh from merged objects, using CSG operations (union, intersection, difference)
• Not produce non-manifold triangle meshes requiring repairs (but read the fine print)
• Write STL and other triangle mesh files directly
• Not be subscription or web-based; your data is yours forever on your local PC

Drawing interface

• Volume-face-edge-point hierarchy with controlled locking
• Sketch-up-like (draw a 2D-2.5D face followed by extrusion into a 3D volume)
• Allows rect edges, polygons, circles, arcs, Beziers and the extruded right prisms from them
• Allows curved surfaces (cylinders, barrel arcs, and Bezier surfaces)
• Allows extrusion of curved surfaces, either parallel or along local normals
• Allows extrusion of text and fonts
• Bodies of revolution (make axially symmetric objects by rotating)
• Lofting (building volumes from cross-sections)
• Tubing (repeating a cross-section along a path and lofting)
• Copy and paste objects
• Reflect and rotate objects
• Group objects and transform (scale and rotate)
• Show dimensions when selected and when drawing/moving/scaling
• Allow dimensions to snap points and also sensible other places (perp to lines, etc)
• Allow units 0.1mm, mm, etc. and snapping tolerances to distance and angle
• Allow multiple materials

Files handled

• Native (LCD) format is human-readable
• Export triangle meshes in STL, AMF, OBJ, or OFF formats
• Export flattened LCD files containing triangle mesh
• Export multi-material model to separate STL meshes
• Export multi-material model to AMF and OBJ along with material definitions
• Always output full normals
• Import STL, AMF, OBJ, and OFF to groups containing meshes as volumes
• Import G-code files and visualise G-code

Slicer and printer integration

• Integrates with PrusaSlicer 2.x, Slic3rPE 1.41 and vanilla Slic3r
• Slice to G-code and preview layers
• Directly upload G-code to an OctoPrint server

Works in progress

• Multi-material slicing
• Directly control and print to a USB, serial or Octoprint connected printer
• Repairing imported triangle meshes

Installing LoftyCAD from the prebuilt installer

Unzip the zip in the Installer directory, to any directory on the Windows system (C:\Program Files (x86) is the standard place for 32-bit programs). The install.bat file will do this (run as administrator!), register the file associations, and create a desktop link.

Installing on Linux and running with Wine

Install Wine according to the WineHQ installation instructions, making sure to enable a 32-bit architecture. Unzip the zip in the Installer directory and run LoftyCAD.exe, opening it with the Wine program loader (double clicking it in the file explorer) On first run it may want to install mono and gecko. It will only run on an x86 machine, and it is only lightly tested, e.g. there are a few crashes with text/font handling.

Building LoftyCAD

LoftyCAD uses the excellent CGAL computational geometry library to merge and intersect triangle meshes.

• CGAL, Computational Geometry Algorithms Library, https://www.cgal.org

Double Helix branch

• This branch is the live development branch and will become the master in due course. Features described above refer to this branch and may not be present in earlier branches.
• This branch has been tested to CGAL 5.5.1.
• This branch is to convert all internal coordinate (Point) representations from float to double, to improve robustness especially when re-importing rendering results as triangle meshes.
• Flattened LCD (FLCD) files are exportable and readable. They are a full-precision connected triangle mesh for re-importing.
• Build as for the Horus and Material Girl branches.

Horus branch

No further development will be done on this branch.

• This branch has been tested to CGAL 5.5.1.
• This branch is to develop a picking replacement to avoid doing the GL_SELECT buffer mechanism, which is very slow.
• Lofting and tubing are implemented in this branch.
• Build as for the Material Girl branch.

Material Girl branch:

No further development will be done on this branch.

• This branch requires CGAL 5.0 (at least; has been tested to 5.5.1) and VS2019 (Community edition is fine)
• The 32-bit version must be used, since LoftyCAD is a 32-bit program for now.
• CGAL from 5.0 is a header-only library and requires no build steps (other than cmake to make all the .slns and vsprojs).
• Some environment variables still need to be set up to build:
• CGAL_DIR --> CGAL checkout location
• BOOST_INCLUDEDIR --> Boost checkout location
• BOOST_LIBRARYDIR --> Boost checkout location
• PATH --> <CGAL_DIR>\auxiliary\gmp\lib added to PATH

Master branch:

No further development will be done on the master branch.

Requires 32-bit CGAL 4.12 checked out to directories alongside, and built from its build instructions.