Create a new surface by clicking [Right mouse click -> Create -> USK -> Surface Preset]. You can set various step sounds for different characters, just use tags.
It will fly off when bullets hit a surface.
Sound of a bullet hit
Audio when a shell touch a ground
Everything is clear here 🙂
Add the Surface script to scene objects and set a Surface Preset in the Material parameter.
Cover value is needed for enemies covers.
Grass value is needed for the stealth feature.