The observed brightness of a Lambertian surface may be written as the product of an albedo factor, p, and the cosine of the incident angle, cos i. This means that brightness can be written as a product of a term that depends on the material, p, and a term that depends on surface direction, which in turn depends on f and g.
| Game | Time | WPM | Accuracy | 
|---|---|---|---|
| 20 | 2017-09-21 10:09:38 | 62.59 | 95% |