Normal mapping is a technique widely used to represent a highly detailed surface mesh using a more simplified low polygon count version of the mesh. Normal maps are widely supported where simplified 3D meshes are a requirement particularly in real time hardware rendering applications such as interactive games.
A normal map is a 2D RGB image that records the surface normal information for a mesh by using the red, green, blue color channels to record the X, Y, Z normal vector data. Each pixel in the extracted RGB image records the normal direction data and is used to determine lighting and shading on the low resolution surface when it is rendered. When you view a normal map on its own it appears in color (compared to a displacement map which has gray tones).
