3D Model Swap

Blender Version: 4.5.1
If you are using a newer version, some steps may look slightly different.

This guide walks you through preparing a custom 3D model in Blender and replacing a League of Legends character model while keeping the original rig and animations.

If you have any questions or feedback, Discord: @hatstore Read the FAQ and the rest of the guide below before you DM.

You can also support me on Ko-fi.

Big thanks to @Frog for making this guide actually readable

Requirements

Tool	Purpose
Lol Aventurine Plugin	Required to import/export `.skn` and `.skl` files in Blender
Blender	Main 3D software for editing the champion model
CATS Blender plugin	Not required, but useful for transferring weights between bones and other things
Paint.net / Photoshop	Edit and export textures (`.dds`)
Paint.net `.tex` plugin	Needed to open and edit `.tex` files
LtMAO	Convert League `.tex` files to `.dds` and back, alternative to the plugin above
Flint	Extract original League champion files (`.wad.client`)
Jade	Edit `.bin` files if skin adjustments are needed
Celestial	Load and test the custom skin in-game

FAQ:

I'm trying to do X why it not working please help?

The answer for why is already in the guide 90% of the time. Re-read carefully and if its still unclear DM and ask.

Why can't I do X in edit mode?

You had likely selected the wrong object. If you are editing the mesh make sure you select the mesh and not, for example, the armature before going into edit mode.

Do I select the green armature icon or the orange one in the objects list top right?

Orange; The green icon can be ignored.

0. Prepare Your Model

Combine Meshes

First import the model you want to swap to. If your model consists of multiple objects:

Select all objects:
Press Ctrl + J to combine them into a single mesh

Texture Display & Materials

Enable material preview (viewport shading)
Select the model and open the Materials tab:
For models with multiple materials (if the materials do not have the textures assigned already, so like if the model is say just solid color):
- Assign the correct texture to each material slot:
If you plan to bake lighting or shadows into the texture, do it at this stage; I really recommend it if you are going for a "realistic" look. (No Divine guide for it yet, but tutorials are out there)

Face Orientation

Enable Face Orientation in the viewport overlays: If the whole model turns red = correct normals orientation, you can skip this step.

If parts don't change color:

Go to edit mode
Enable X-Ray
Select the full mesh (drag select)
Press Alt + N → Flip

If only some areas are not red, select those faces individually and flip them.

Disable Face Orientation once done.

Merge Vertices (IMPORTANT)

Enter Edit Mode
Select the full mesh
Press M → By Distance
In the window that pops up bottom left, set the distance to 0.001 – 0.005

This step removes duplicate vertices and prevents major issues later.

Decimate (Vertex Limit)

League models must be under ~65,000 vertices to be imported.

Enable Statistics in the viewport
Hide any non-custom meshes (H)
Check vertex count (aim for <60k)

If too high:

Go to the modifiers tab:
Add a "Decimate" Modifier
Use Collapse Mode
Enable Triangulate
Lower the ratio until vertex count is acceptable

If quality degrades too much:

Try Planar Mode with UV Delimiting enabled
You can even stack both collapse and planar decimates if needed

1. Edit Your Model to Fit the League Rig

1. Import the League Model

Import the League champion model for reference

2. If the Custom Model Has an Armature

Select the armature (orange icon not the green)
Enter Pose Mode
Move/Rotate bones to match League proportions
Once you're done, duplicate the Armature Modifier, apply the top one

In Pose Mode, press Ctrl + A → Apply Pose as Rest Pose
Continue editing

3. Edit Without Using an Armature

Select the model
Enter Edit Mode
Press O to enable Proportional Editing
Move vertices to reshape the mesh
Use the mouse wheel to adjust influence

If unwanted areas move:

Enable Connected Only in proportional editing:

2. Combine UVs & Textures

(This part can be annoying, if there are too many materials and you have installed the CATS plugin go to the Material Atlas guide page and follow that.)

If the model uses multiple textures:

Combine them into a single texture kinda like this:

UV Editing

Go to the UV Editing tab:
Enter Edit Mode with the just mesh selected
Select a material in the materials tab (make sure you have no other vertices selected before)
Replace its image with the combined texture here:
Click "Select":
The vertices with that material will light up like this:
Scale and move the selceted parts in the UV windom on the left to fit the new texture (change the background image to your new one in the box shown above to make that easier).

Repeat for all materials until all of them use the combined texture and the model looks correct in the viewport.

You can now delete all materials except one.

3. Weights & Rigging

1. Parenting

If the model already has an armature:

Select the mesh
Press Alt + P → Clear Parent (Keep Transformation)

Then:

Select the mesh
Shift-select the League armature
Press Ctrl + P → Armature Deform

2. Transferring Weights

Follow this guide to transfer weights from the League model:

After transfer:

Hide the League mesh
Select the armature
Enter Pose Mode
Rotate bones to test if the weights transferend correctly. Pay extra attention to the fingers, and any detached parts.

My rule of thumb is you should be able to rotate a bone ~90° without the mesh starting to look weird. It will most likely be really off in some places. To fix it, exit pose mode and go to step 3: