Which texture map is used to add fine surface detail such as scratches and ridges without changing geometry?

• A. Albedo Map
• B. Emission Map
• C. Metallic Map
• D. Normal Map

Answer: (D)

Normal maps let you add fine surface detail without extra geometry by encoding per-pixel surface normals that influence lighting. The RGB values represent a normal vector (typically in tangent space), and the shader uses these perturbed normals during lighting calculations. That means scratches, ridges, and other micro-variations catch light differently, creating convincing bumps and texture without increasing polygon count.

Albedo maps control the base color, emission maps make surfaces glow, and metallic maps adjust how metallic the surface appears in lighting. None of those alter shading in the same per-pixel, bump-like way as a normal map, which is why it’s the one that produces fine surface detail without changing geometry.