DISCORD: https://discord.gg/2wxM5WYBev

DOCUMENTATION: https://docs.google.com/document/d/1YE0Cf5bKtGy7aLxS_KrnFIR6cAq6QVtRpxiJCSkN0nk/edit?usp=sharing

What this plugin does

Material Slot Cleaner is an Unreal Editor plugin. It finds Static Mesh assets with duplicate or unused material slots, shows a Preview of how Clean would remap those slots, and can then clean them. You can also replace one material with another. 

It does not delete material assets or source FBX files. Analyze and Preview never change your meshes. Only Clean Selected, Clean All, or Apply Replacement writes to assets.

Options 

- Merge identical. Combine slots that use the exact same material asset. 

- Remove unused. Drop slots that’s not used. 

- Keep the first occurrence. When merging, keep the first slot that has that material.

How to use 

1. In the Content Browser, select Static Mesh assets. Folders, materials, and Blueprints are skipped. 2. Click Refresh Selection. 

3. Click Analyze. This inspects slots only. It does not change or save assets. 

4. Click a mesh row and read Preview (Usage and Mapping). Mapping is what Clean would do: a new slot index, or

 Removed. 

5. Optionally tick cleanup options or add material replacements. 

6. Click Clean Selected or Clean All. This is the only action that remaps or removes slots.

7. Press Ctrl+Z to undo. Unreal marks changed assets dirty. Save them yourself when you are ready. A default mesh with one used slot does not need cleaning. If there are no duplicates or unused slots, Status stays Clean.

Material replacement (A to B) 

Pick a From material and a To material, then click Add. The list shows From and To; use Remove to drop a rule.

- Apply Replacement. Writes A to B on the selected meshes now (or on every listed mesh if none are selected). It does not merge or remove slots. 

- Replace materials when cleaning. When ticked, Clean applies those A to B rules as part of slot cleanup. Preview Mapping includes them only when this box is ticked.