What is the primary function of a normal map compared to a height map?

The primary function of a normal map is to specify surface direction, which significantly contributes to how light interacts with the surface of a 3D model. Normal maps contain RGB information that relates to the orientations of the surface normals, influencing how light reflects off the surface and creating the illusion of finer details without increasing the geometric complexity of the model.

On the other hand, a height map provides grayscale information where the intensity of gray indicates the height at each point on the texture. It serves to represent elevation changes but does not directly alter the surface normals as a normal map does. Thus, while both maps add detail and depth to textures, they operate in fundamentally different ways, with the normal map enhancing the lighting effects and the height map being focused on the elevation of the surface. This distinction is crucial in game design, allowing for efficient creation of visually rich environments without burdening performance with excessive model details.