LDD uses its own brick definitions, which are different from LDraw definitions, and only a subset of the bricks made by LEGO are available for use. In 2004, the LEGO Group released its own 3D LEGO CAD software, called LEGO Digital Designer (LDD for short).

In the following years many programs were developed that use the LDraw file-format, such as LeoCAD, a Windows LDraw-based editor (1996), L2P/元P, an LDraw to POV-Ray converter (1997/1998), and MLCad, a Windows LDraw based editor (1999). Jessiman died in 1997 at age 26, but the LDraw file-format survived, and is under continuous maintenance and extension by the LDraw community. In order to describe the bricks, Jessiman defined a file-format, a set of rules to describe a LEGO brick within a single text file, and an editor called LEdit. In 1995, James Jessiman created LDraw, a program originally intended to create images of LEGO bricks. Virtual building is a form of 3D CAD (Computer-Aided Design). Lets first look at some history and define some terms. It serves as a general inroduction to a three part series: Guide to LEGO Digital Designer, Guide to Stud.io and Guide to Rendering. This help page will explain the background behind virtual building and what software you need to use. These files contain virtual models, and you need special software to view and build these models. However, many other MOCs have their instructions in other formats: Many Rebrickable MOCs have instructions in the form of a PDF file, that contains a series of photographs showing different stages of building. All of that can be done on almost any computer, and almost any operating system.

Besides the obvious more bricks, more colors, and easy searching a virtual model can be used to generate building instructions, and it can be rendered, in other words, the model can be used to create photo-realistic images. Surely, it is much more fun to build with real bricks, but virtual building has several advantages. Virtual building means building a LEGO model on a computer, using virtual LEGO bricks. Did you ever wish you had more LEGO Bricks? Or wish you had a certain LEGO brick in another color? Did you ever wish you could instantly find a particular LEGO brick? If so, you should really try virtual building.

Lego digital designer 4.3