- Diffuse (Lambertian) reflectance model
- Some light is absorbed (function of albedo p)
- Remaining light is scattered in all directions
- Specular Reflectance
- Reflected direction depends on light orientation and surface normal
- e.g. mirrors are fully specular
- Most surfaces can be modeled with a mixture of diffuse and specular components
- Specularity
- A spot where specular reflection dominates (typically reflects light source)
- Albedo
- Bidirectional Reflectance Distribution Function (BRDF)
- A fundamental function that describes how light is reflected with three components - normal, light, and camera
- Observed intensity depends on light sources, geometry and material of reflecting surface, surrounding objects, camera settings
- Surfaces in a scene cast light and shadows on each other
- Intensity variations are important cues for understanding images