Appearance

Shading(Lumination, Shading and Graphics Pipeline) ​

关于

照明, 着色和图形管道

What We’ve Covered So Far (到目前为止我们已经涵盖了什么) ​

Shading ​

Shading: Definition

对不同的物体应用不同的材质的过程

Blinn-Phong Reflectance Model ​

A Simple Shading Model (Blinn-Phong Reflectance Model) (一个简单的着色模型 (Blinn-Phong反射模型))

Perceptual Observations (感性的观察)

Shading is Local (阴影是局部的)

Compute light reflected toward camera at a specific shading point (计算在特定位置反射到相机的光 阴影点)

Inputs:

  • Viewer direction, v (观察方向)
  • Surface normal, n (表面法线)
  • Light direction, I (for each of many lights) (光照方向，I(多个光源中的每一个))
  • Surface parameters(color, shininess, …) (表面参数(颜色，亮度，…))

No shadows will be generated! (shading ≠ shadow) (没有阴影将生成!（ 阴影 ≠ 影子 ）)

Diffuse Reflection ​

Diffuse Reflection (漫反射)

  • Light is scattered uniformly in all directions (光在各个方向均匀地散射)
    • Surface color is the same for all viewing directions (表面颜色是相同的所有观看方向)
  • But how much light (energy) is received? (但是接收了多少光(能量)呢?)
    • Lambert’s cosine law (兰伯特余弦定律)
  • 光照衰减

Lambertian (Diffuse) Shading (兰伯特漫反射着色)

Shading independent of view direction (着色独立于观察角度)