Since displacement mapping is applied to the geometry of a surface, rather than to its shading, the normals of a displaced surface must be perturbed in tandem with the actual displacement in order for things to look correct in the render.

• 因为置换贴图是赋予到一个表面的几何体上，强于赋到它的材质上，显示表面的法线必须用实际的置换来扰乱，为了在渲染时校正正确的外观。