LDraw is a system of free software tools, with which you can create three-dimensional Lego models on the computer.


The LDraw file format was developed by James Jessiman ( born June 8, 1971, † 25 July 1997) developed as a DOS-based display program and a simple editor. The file format itself is a human-readable, platform-independent and line-oriented ASCII code, which can be, in principle, written and edited with any text editor. James Jessiman has also written many of the original components, which are part of the collection. This steadily over time expanded library constitutes the core of the applications, the use of all programs and models. James Jessiman died in 1997. Since then, many applications have been written for various platforms, which all use the same file format and the large block library. With the help of some conversion programs and the free 3D renderer POV- Ray allows you to create photo-realistic images of Lego models.

File Format

The LDraw format can divide the models in construction stages and display it in different angles, so you can create complete building instructions. Models can also be incorporated as parts in larger models. This modular design will make it easier to create more complex components or models.

The file extensions used are:

  • . dat - old name for all files. Today, the suffix should be used only for files of the component library.
  • . ldr - new file extension for files that describe the individual models. The format is similar to the above, new meta - commands can be version 1.0, however, included.
  • . mpd - a " Multipart Document" may include several models.


Model ( editors )

While it is possible to describe Lego models alone with part numbers and absolute coordinates in the three-dimensional space. But because the process is quite tedious, programs have been developed to simplify the construction process:

  • Ldraw and ledit
  • MLCad
  • German language module for MLCad
  • Bricksmith
  • LeoCAD

Viewing programs

  • L3Lab
  • LDLite
  • LDView
  • Ldglite


  • L2P and L3P
  • LDraw2LWSVorlage: Web archive / Maintenance / Nummerierte_Parameter
  • Ld2vr

Publication tool ( LPub )

The editors mentioned above usually offer although a rudimentary print function on, sophisticated construction management can thus create but only limited. Especially in more complex models with sub-steps, callouts, exploded views or parts lists these programs come quickly when printing to their limits.

To address this problem, the programming and Lego fan Kevin L. Clague has developed a standard for LDraw compatible program LPub Names can be created with the professional building instructions, which can stretch which can be compared to the original Lego models.

In order to describe the layout of the building instructions, a number of new so-called Meta -Comments have been introduced that are stored in an LDraw model file along with the actual components as comments. This worked with the LPub models remain compatible with all LDraw programs, as these ignore the comments when processing the model file simply.

Version 2

To generate ( rendering) of each building steps and the overall model Povray was used in this version yet. Due to the complex rendering process could take several hours to create a larger building instructions. Were noted error in the result in the connection, had this process after troubleshooting again be performed. Since photo-realistic images are not necessarily needed in a construction manual and shiny surfaces, light reflections and shadows can be a hindrance when reverse engineering sometimes, the generation of the graphics was selectively incorporated into later versions of the viewers Ldlite or LDView.

In this version the user were still demanded a lot of imagination when it comes to the later appearance of the manual. The individual layout commands had to be manually entered into the model file, and only after the lengthy build process, the result could be examined. LPub in this version was so still no independent layout editor, but rather an output generator.

Version 3

In this version the first time Ldlite or LDView could be used as a rendering programs, which significantly accelerated the creation of the manual and troubleshooting. In addition, there were some improvements, but the development in favor of the version 4 was set quite quickly.

Version 4

The current version 4, which was released recently, now follows the approach of a WYSIWYG editor. The layout of the instructions can be edited with the mouse and menus. Many of the functions that had to be laboriously entered in the earlier versions, can now be accessed via appropriate menus. After each change of the layout, the display is updated so that potential errors can be identified and corrected. Since the program is still at an early stage of development, but all functions are not yet integrated into the user interface. However, it is possible to type in the not so far as supported functions, a built-in text editor manually.

  • LPub