Basically, one image alters the shading of a second image, in order to create the illusion of depth/height, like ridges or folds.
This ‘fake’ appearance of depth/height is based on the brightness values of the first image. White gives the highest height, and black gives the lowest. All values of gray give a range of height in between. |
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EXAMPLE: In both textures, the blue color wraps around the light/dark areas of the gray. The first Shadow has a higher contrast, and so the folds it creates are more pronounced.
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