What distinguishes a Normal Map from other textures in Unity?

A Normal Map is distinguished from other textures primarily by its color, specifically the way it encodes surface detail. Unlike typical color textures that define the base color of a surface, normal maps utilize RGB color values to represent surface normals at various angles. This allows the rendering engine to simulate complex surface details like bumps, wrinkles, and grooves without physically altering the geometry.

The RGB channels in normal maps correspond to different axes in 3D space. For instance, the red channel often influences the x-axis, the green channel the y-axis, and the blue channel the z-axis. This encoding allows for intricate lighting effects and depth perception on a flat surface, making the object appear more detailed and realistic without a significant increase in polygon count.

Other aspects, such as resolution, format, and size, do play roles in the performance and quality of texture mapping in Unity, but they do not define the unique function of a Normal Map. The fundamental distinction lies in how it manipulates lighting based on surface normals, which is key to achieving realistic visual effects in 3D environments.