## Surface Types
Based on the direction of reflection a body might be classified as
- **Diffuse** - Energy striking a surface is scattered in all directions. Think of a white sheet of paper
- **Specular**- energy is reflected at an angle equal to an angle of incidence. Think of a mirror
- **Mixed** - Most real surfaces are a combination of above two. It is characterized by "specular fraction" - i.e. fraction of total reflected radiation that is specular