What exactly is "normal" data?(direct3d 11, c++) <p>I heard the term normal data many times before in direct3d games. But I never knew what it means. I tried searching in google for results, but most of them gave vague explanations about Normal data.</p> <p>From what i understand, normal data is used for lighting calculations, such as diffusion, ambient and directional. But that's pretty much all i understand.. </p> <p>Can someone explain to me why we use normal data? and what exactly is normal data?</p>