Lecture 6 (Illumination Models) Flashcards
What are the different surface types?
- Self-luminious
- Refractive
- Translucent
- Reflective (diffuse)
- Reflective (specular)
Give an example of a self-luminious surface type.
The sun
- Any object that emits its own light
WTF is a ‘Refractive’ surface type? And give an example
Changes direction of light as it passes through (due to change in transmission medium)
e.g. Water or glass
WTF is a ‘Translucent’ surface type?
Scatters light that passes through it
Break down Reflective surface types.
Diffuse and Specular
WTF is a ‘Reflective (Diffuse)’ surface type?
Reflects light in all directions (scattered)
e.g. Carpets, Rugged surfaces
WTF is a ‘Reflective (Specular)’ surface type?
Reflects light at the same angle as the incidident ray
e.g. Glossy surfaces, polished steel
WTF is the difference between ‘Diffuse’ and ‘Specular’ surface types?
Diffuse reflects light in all directions (scattered).
Specular reflects light in one direction.
What factors must be considered when choosing an illumination model?
Realism and computational cost.
Must balance between the two.
What are the components of light?
- Ambient
- Lambertian (diffuse)
- Specular
WTF is ‘Ambient’ component in lighting?
Light rays coming UNIFORMLY from all directions hitting the object
WTF is ‘Specular’ component in lighting?
Highlights and glossiness
WTF is ‘Phong Illumination/reflection model’?
Combines all three components of light
- Ambient Illumination
- Lambertian (diffuse) Reflection
- Specular Reflection
WTF is an ‘Isotropic Surface’?
The relationship between the incoming and outgoing direction of light is the same over the whole surface (otherwise anisotropic)
- Illumination models generally only consider isotropic sufrace
What is simple illumination models?
Do not consider shadows, reflections or photon-based effects