LeoCAD is an easy-to-use and easy-to-get-into 3D modelling application that is used to create virtual models using LEGO® and other bricks. It is one of three 3rd party editors to be used with the, probably most, extensive LEGO brick model collection of LDraw.
Although other LEGO brick CAD editors exist, LeoCAD is considered great for Windows and Linux operating systems. It is also available for macOS. LeoCAD is available under the GNU Public License v2 and according to its official website, it will always remain free.
According to their website, the term “LDraw” can be used to refer to the original DOS-based LDraw program, the LDraw parts library, the LDraw file format or the LDraw System Of Tools.
LeoCAD is compatible with the LDraw parts library, the LDraw file format and some of the related LDraw Tools. Since LDraw‘s original author, James Jessiman, passed away in 1997, the parts library is being maintained and extended by LDraw community members. It also uses the brick colours determined by LDraw.
The LDraw parts library gets updated very regularly with official LEGO bricks and sometimes other brick formats too. At the time of writing it had more than 100 000 core parts (called core library files) which are automatically included with the installation of LeoCAD. Additional, unofficial parts can also be downloaded from LDraw and your own custom libraries can be created.
The front end is intuitive and includes various features for even advanced users. LeoCAD can not only save models as .LDR, .dat and .MPD files, but can also Export to 3DStudioMax (.3DS), COLLADA (.dae) and Wavefront (.obj). Blender works well with .dae and .obj files too.
A nice feature of LeoCAD is its Minifig Wizard which allows comprehensive customisation of the standard LEGO Minifigure before inserting it into the building area (and exporting it to other platforms). Most of the Minifigure parts are also available in the Parts section, but by using the Minifig Wizard they will be grouped as one. Apart from using this feature to make your own Minifigures, it is also handy to add a quick figure to get an idea of the scale of your model.
The Minifig Wizard is available under Piece in the top menu bar. Completed figures are inserted by simply selecting OK.
Yet another nice feature of LeoCAD is that it supports basic animation. Animations are mainly used for creating files with built-in building instructions. After the frames are set by using the forward and backward arrows, the same buttons are used to cycle through the steps.