What is Sollumz?

Sollumz is a Blender add-on designed for Grand Theft Auto V modding that allows users to import, edit, and export game assets in CodeWalker XML formats such as .ydr, .ydd, .ybn, .ymap, and more. It streamlines the workflow for creating or modifying props, vehicles, interiors (MLOs), and other assets directly within Blender by handling materials, collisions, bones, and animations. By integrating seamlessly with GTA V’s asset pipeline, Sollumz provides an all-in-one solution for modders who want to bring their creations into the game without relying on multiple external tools.

Programs we will need

Blender
CodeWalker
Sollumz
All the above programs and plugins are FREE and do not cost anything to use.

Installing a Blender Plugin from file

Now that you have Blender up and running and have Sollumz downloaded, we need to install it. Navigate to Edit>Preferences>Add-ons>Arrow>Install from Disk, from here navigate to your downloaded Sollumz file and select it, and click Install from Disk. After that a new Add-on will be added to your Blender, you should now see "Sollumz" in the list.

Importing your first model

I cannot stress this enough, you need an unlocked car model for this. Using a locked model and exporting the XML violates ToS of almost every dev. This would be considered "unlocking" or "ripping". Only use this tutorial on unlocked cars you have rights to use. WildFyr Development is not responsible if you use this tutorial in malicious ways.

To import a model using Sollumz we need to export the YFT as an XML. Grab your model and bring it into CodeWalker's RPF explorer, right click and select Export XML. Create a new Blender workspace and go to File>Import>CodeWalker XML (If you do not see this, ensure you installed the Sollumz plugin correctly and it is activated). The first thing you will see after it imports is a giant box, don't freak out, this is simply the vehicle collisions. Open the collection in the hierarchy and open the COL and select every collisions and press the H key in the view port to hide everything.

If you have both a _hi.ytf and a normal .ytf, make sure to import the normal YTF first, then the HI to ensure LODs are import correctly.

Hiding Collisions to make modelling easier

Sollumz and LODs

Sollumz supports Level of Detail, a very useful feature in video games. Level of Detail (LOD) in video games is a performance optimization technique where multiple versions of a 3D model—with varying polygon counts—are used depending on the object’s distance from the camera. High-detail models are shown up close, while simplified versions are used farther away, reducing the amount of geometry the game engine needs to render at once. This helps improve frame rates and overall performance without noticeably affecting visual quality. For GTA V car developers, LODing their models is essential because vehicles are often seen from varying distances; properly set LODs ensure smoother gameplay, faster loading, and better performance for players without sacrificing visual fidelity up close.

To switch between the different LOD modes, you can do it in 2 separate ways

The Whole Model

To change LODs on the entire model all at once, open up the Sidebar (Small left facing arrow on the top right side of the viewport), and select the tab for Sollumz Tools. From there you can select General and under Level of Detail select from Very High - L0, High - L1, Medium - L2, Low - L3, and Very Low - L4.

Single Parts

You can also change the LOD of a single part, allowing you to work on one thing at a time, or see what a single part would look like from afar. This is not something you can do with other programs like Zanoza Modeler 3 where you can only ever see every LOD from each tier without dismissing the compounded object. To switch between the single LODs on individual parts select the part and go to the Data tab, then Sollumz LODs, and click on the LOD name. This will transform the object to display the LOD selected, whilst leaving every other part at the global LOD setting.

If the LODs are blank, this means no LOD was detected for that part. You might not have imported the model correctly, or the model does not have LODs. You can click on the open area to select a mesh to be the LOD.

Generating LODs

This is not the recommended way of LODing, but in a pinch it works. Under the Sidebar's Sollumz Tools, you can enter the Drawables tab, and use this to Auto LOD. This will apply the Decimate Modifier to the mesh, and automatically apply them to the respective LOD positions. I recommend at least hand LODing L1, by the time L2 and the rest come around it will be so far away making out details will be next to impossible and decimating is fine.

Blender's UV Maps

Blender has support for multiple UV maps, something GTA uses a lot on their cars. To switch between them, you can select them in the Data tab under UV Maps. This is most useful for creating body templates for liveries, as vehicle liveries use the UVMap 1 UV, instead of UVMap0. But many other parts use multiple UV Maps aswell.

Exporting back to YFT

Once you have finished all your modifications and want to export the model back to a game ready model, simply select the model's parent in the hierarchy (This is the highest most node, and has the same name as your model). In my example, it is 23tahoeppv. Once it is selected, head to File>Export>CodeWalker XML.

:::Info

If you do not select your model's parent, nothing will export. If it did export correct, Blender should give you a little blue pop-up in the bottom of the window telling you that it did export, and how long it took.

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Then we will head back over to CodeWalker to import the XML file back to a YFT. In CodeWalker's RPF explorer, right click and select Import XML. Find your now exported XML file from Blender and open it, CodeWalker should refresh and your exported model should not be available. You can drag the YFT file out and back to your game/server files for use.