ABSTRACT
Many real-world objects such as brick walls and paved grounds have bumpy surfaces. The surface normal irregularly changes across the bumpy surface, and so do the intensities of the lit surface, making the bumpy features clearly visible in the rendered result. Using two- dimensional (2D) graphics packages, the RGB colors are converted into gray scale, and the gray scale image is often edited by hand to produce the height map. Then, the height map has the same resolution as the image texture. The low-resolution mesh used for normal mapping, such as the quad, is named the base surface. It is raster zed and each fragment is passed to the fragment shadier, which will fetch a normal from the normal map to light the fragment. Normal mapping gives the illusion of high-frequency surface detail in that it is achieved without adding or processing more geometry. Texturing is described as 'pasting' a texture on an object surface. Visualizes a normal map in a cross section.
