Parts Library

LeoCAD is completely compatible with LDraw's Parts Library. In fact, the library included in the installer packages is just a zip archive of LDraw's library without any changes.

This is done mostly to simplify things for new users so they don't need to download and install a separate file or worry about updating their library. A lot of LeoCAD's users are young people without a lot of computer experience so the setup process is kept as simple as possible.

At the same time there are experienced users who like to maintain their own libraries with unofficial parts that they create or download from the internet. Those people can share their LDraw library with LeoCAD and use it directly, all they need to do is point LeoCAD to it.

There is a performance advantage when using a zip file for the library, the application will take less time to start and models will load faster.

Using a Custom Parts Library

There are several ways to specify a custom library folder or file (in order of priority):

  • Use the -l command line option followed by the library path
  • Set the LEOCAD_LIB environment variable
  • Enter a new library path in the Preferences Dialog

Note that LeoCAD can use either a zip file or a regular folder for its library. Here are some examples:

$ leocad -l C:\LDraw\
$ set LEOCAD_LIB=C:\User\Downloads\

Unofficial Parts

You can easily use unnoficial LDraw parts with LeoCAD. If you are using your own custom library with loose files then all you need to do is make sure you update or delete parts.lst and the parts should be visible next time you start LeoCAD.

If you're using LeoCAD's default library then you'll need to download the current unofficial parts from, place in the same folder where library.bin is located and restart LeoCAD.

Default Library Path

The default library path is different for each OS:

  • Windows: The program looks for library.bin in the same folder where LeoCAD.exe is located
  • Linux: This is set at compile time but it's usually /usr/share/leocad/library.bin or /usr/local/share/leocad/library.bin
  • FreeBSD: The default is /usr/local/share/leocad/library.bin
  • Mac OSX: The library.bin file in the Contents/Resources folder inside the application bundle

On Linux you can set the install path prefix at compile time by passing it to qmake:

$ qmake INSTALL_PREFIX=/my/path

This will change the default library path to /my/path/leocad/library.bin

Last modified 20 months ago Last modified on Mar 12, 2015 9:59:23 PM