What is the difference between roughness 3D model and Procedural 3D model?

Roughness 3D models define surface texture properties (like smoothness or unevenness) to control how light interacts with a material, while procedural 3D models are generated automatically via algorithms instead of manual creation. Roughness models are part of texturing—they add realism to surfaces, such as a scratched plastic toy or polished ceramic. Procedural models use rules (e.g., "generate 50 rocks with random shapes") to create scalable, consistent assets quickly. Use roughness for material detail (like a game character’s skin); use procedural for lots of similar objects (like a city’s buildings) to save time.