LEGO abandoned the maintenance of LEGO Digital Designer (LDD) on Januari 31, 2022, but LEGO wasn't actively providing updates since 2019. In 2020 a small group of enthousiasts found a way to continue to support LDD by adding new colors, new parts, new prints etc.

I am adding a lot of new parts to LDD myself, in order to recreate official LEGO sets in LDD. So why not share my work with the rest of the LEGO digital building community?! This was first done through a post on the Eurobricks forum, but evolved to a more structured way with this website, and even a Patreon where you can support me in continuing this website and LDD updates.

Let's start with the folder structure. Within the LEGO Digital Designer folder in AppData → Roaming → LEGO Company, there are two folders: db and Palettes. The db folder is the most important one, we will come back to that one. The Palettes folder contains some pre-structured files which can act as a shortcut. Basically: you can create a custom parts palette with LDD. It also holds the LDDExtended color palette. More on that can be found in a future blog post.

The db folder contains all your important files and is structured with the following folders:

• Assemblies: contains all part assembly files in *.lxfml format.
• Decorations: contains all decoration files in *.png format. LDDUpdates will give an extra folder here called UV Maps, this will show you the position of a decoration in order for it to show up in LDD.
• MainGroupDividers: contains images for all the part group buttons in LDD.
• MaterialNames: here the names of colors are stored.
• Primitives: contains both the 3D files (in *.gx (where x can be a number) format in the LOD0 folder) and information in *.xml format (containing the part name, collision and connection data).

The following files are located here as well:

• CurrentMaterials: determines which colors are currently used by LEGO, more on this in a future blog post.
• DecorationMapping: contains a mapping of decoration files to partIDs.
• info: contains some version info of LDD, will not be used.
• Materials: contains the RGB values of colors.
• pes: contains some version info of LDD, will not be used.

That is always a good question! There are multiple sources 3D meshes come from: LDRAW, the LEGO Building Instructions app. And in the future hopefully BioPack for BIONICLE parts for example. The access to parts from the LEGO Building Instructions app has opened a lot of opportunities for new parts. But that is all very near future! For the somewhat more distant future you can expect the following: more BIONICLE parts and optimized decorations (a blog post for this will follow as well) to decrease LDD load times.

I am investigating how to create an installer. This way updating your LDD will be so much easier. No more copy-paste, just download the *.exe file and run it. It will do everything for you.

This can happen. I try to prevent this from happening, but LDD is always being improved. And the way UV maps are handled as well. UV maps determine how decorations are applied to 3D shapes. Sometimes they will be optimized. All LDDUpdate decoration files will be updated accordingly, but your custom files not of course. Most of the times it is a matter of re-scaling or re-locating the position of your decoration.

I try to limit these things, but they can and will happen. For a big end-2024 update the torso (part 3814) will be updated for example. It will include both the front, rear, and left and right arm UV maps in one decoration. This brings the amount of needed decorations back from 4 to 1. The same will happen for leg parts. Leg assembly 21019 has already been updated and combines 12 decorations into 1 file! Same has happened for the new Minifigure head 28621: the back and front are defined in one decoration file. In the future this will also happen with the original head (3262).

Sorry if this causes inconveniences for your custom decorations, but in the end I am here to improve and modernize LDD. These changes are not taken lightly though, they are well-considered if the benefits outweighs the disadvantages.

Myself, Stephan (also known as Stephan3321 on Mecabricks and Eurobricks), and jester (known as Stas on Mecabricks and jester on Eurobricks). Polymaker kindly provided a software where parts can be given collisions and connections.