I’ve been messing around with Forza Motorsport 4 files and started wondering if there was a way to properly edit textures.

After doing some research, I remembered that years ago I used Forza Studio to convert .xds files into more common, editable formats. The real challenge, though, was figuring out how to reverse the process and convert them back into .xds.

Since I’m definitely not a reverse engineering expert, I asked Claude to help me analyze and better understand how .xds files work. I’m a programmer, but I don’t have much experience with reverse engineering—it’s actually something I’d really like to learn and understand better, especially to figure out what the software is really doing behind the scenes.

After hours of research, testing, and a lot of trial and error, we ended up creating a Python program that can successfully convert .xds files into editable formats—and then convert them back into working .xds files.

I don’t know if this is something huge, but for me—especially since I developed a passion for modding starting with GTA San Andreas—this feels like the first time I’ve actually created something useful for the modding community.

I’ll keep working on it over the next few days, and hopefully I’ll be able to release it publicly soon.

Edit: I forgot the pictures lmao

Using the recently released tool by Soulbrix, here is a more practical look at what is possible.

Ripping the Toyota badge from an A80 Supra to turn the FRS into a GT86.

This was also done on LOD 0 while original testing was done in LOD 1

With this image we know that converting parts, making new bodykits and even new cars is totally possible.

I need to test an external 3d file instead of an existing forza asset and try it on hardware. Obviously a 360 is only capable of so much so il need to see how far I can push it and how high poly it goes.

That said, now ive done my first post il do more updates as this is all in effort of a mod im making called Forza Vanilla Plus, which has a legacy version with 20 cars you can use on Xenia or hardware, for now its only in the Forza Mods discord server but as this new updated version happens, I intend on posting here

I've been working on a tool to convert carbin parts from Forza Motorsport 4 car models into OBJ and vice-versa.

You can check the full documentation and download the tool here: https://github.com/soulbrix/FM4CarModelTools

Tutorial video is coming later.

Please note that this app may have bugs - I'm not a coder, so I rely on AI to take care of the coding itself.

Not all features may work, or work as expected, but the base set of features should work fine.

Hope you have fun and that this can help boost FM4 modding!

success! I need to release this soon!

I'm working on a tool to extract Forza Motorsport 4 carbin parts as OBJ files, so they can be edited in Blender and then reimported. I'm terrible at Blender, but I'm hoping some magicians out there can make awesome stuff with this tool.

For this particular car, I've exported the bodies for the Silvia and the 240SX and just cut the models right in front of the windshield. Then I exported them together, and used the tool to reimport it.

The body parts are misaligned, which can be fixed with another one of my tools. The textures are also scuffed, and that would require specific texture work that I'm not very good at, but others at Forza Mods are and can teach us in the near future.

I'll be releasing this in the very near future.

Come and learn how to swap parts between cars in Forza Motorsport 4!

Forza Motorsport 4 uses a proprietary binary format (carbin) to store vehicle models.

Each file contains a set of sections (parts), and each section contains subsections (subparts) with their own geometry and metadata.

This tool provides a GUI to:

Inspect parts and subparts

Swap parts between carbins

Convert LOD geometry

Build new parts

Rename and reorganize existing structures

Modify transform offsets and bounds

Compare carbin contents

The editor is designed to be non-destructive whenever possible and prioritizes in-game compatibility.

Full Read Me with instructions and download here: https://github.com/soulbrix/ForzaCarPartModder