When a single object has more than one material, you can press this button to generate a vertex group which identifies the faces the material is assigned to.
This is expecially useful for correctly separate multiple displace modifiers
![](https://docs.extreme-addons.com/wp-content/uploads/2022/04/Vertex-groups-1024x561.jpg)
When a single object has more than one material, you can press this button to generate a vertex group which identifies the faces the material is assigned to.
This is expecially useful for correctly separate multiple displace modifiers