Tutorials: How to vary reflection smoothness according to incidence angle

In this material and rendering tutorial the ability to vary the degree of surface roughness according to view angle is explored. This is a powerful technique that simulates real world material properties which can be useful for architectural and product/package design. Here are some links to an architectural website which demonstrate examples of the technique from this tutorial. Example 1. Note the ceiling. Example 2. Note the floor. It’s very rough with only a hint of glossiness near the lower part of the image, but at the distant end of the scene it’s more glossy. Example 3. Compare the wood