How can you use a decal system in Unity to add details without extra geometry?

• A. Decals project textures onto surfaces to add details without adding geometry.
• B. Decals replace the underlying material.
• C. Decals generate additional mesh geometry.
• D. Decals are only for UI.

Answer: (A)

Decal systems add surface detail by projecting textures onto existing geometry rather than adding more polygons. The decal texture is projected onto nearby surfaces within the decal’s volume and blended with the underlying material, letting you simulate scratches, dirt, bullet holes, graffiti, and other details without changing the mesh. Because no new geometry is created, you get richer visuals with lower polygon costs. Decals don’t replace the base material and aren’t limited to UI—they work on world geometry, terrain, and props. In Unity, you typically place a decal and assign a material that defines how the projection blends with the surface (albedo, normals, roughness, etc.), so the detail moves and updates naturally with the scene.