Suppose we build a model of a sphere using many polygons and color it with one color. We get something like. Why does the image of a real sphere look like this? The reflected light is …

Triangle Shading Algorithms Given the lights and materials in the scene, how do we compute the color at a given point on a triangle ? Three main types Flat shading (per polygon) Gouraud shading (per …

A shading model checks lighting conditions and figures out what surface should look like based on lighting conditions and surface parameters: Amount of light reflected (and which color(s))

Illumination Vs. Shading Illumination (lighting) model: determine the color of a surface point by simulating some light attributes. Shading model: applies the illumination models at a set of points and …

Uniform Shading Assumptions 1. The surfaces really are polygonal. • N = surface normal = constant

With pixel shaders on programmable graphics hardware, it is possible to achieve Phong shading by using a small program to compute the illumination at each pixel with interpolated normals.

This has some special-purpose uses, but not really good for drawing a scene. Often used to add color to a surface by circumventing the shading computation.