Lightning & Shading Flashcards
1
Q
directed / parallel light source
A
Position is point at infinity: (x, y, z, 0)
2
Q
point light source
A
finite point source: (x, y, z, 1)
3
Q
spot light source
A
position, direction, opening angle
4
Q
ambient light source
A
light comes from all directions
5
Q
realistic light source: area light
A
- Every point on a (plane) surface emits light like a point light source
- more realistic, particularly for shadows
6
Q
realistic light source: Image Based Lighting (IBL)
A
- Every point in a (half-)sphere at infinite distance emits light in all directions
- Light color often comes from a 360° high dynamic range photograph
- This is the default setup in many realistic state of the art applications (e.g. see Substance)
7
Q
Types of reflections
A
8
Q
What is the wording of BRDF
A
Bidirectional reflectance distribution function
8
Q
reflection distribution
A
9
Q
What is BRDF doing?
A
The BRDF measures how much of the incoming light (irradiance) at a surface point is reflected in a particular outgoing direction (radiance). It describes:
- Surface properties: Smooth surfaces (e.g., mirrors) reflect light in specific directions, while rough surfaces scatter light in multiple directions.
- Reflection behavior: The BRDF depends on both the incoming light direction and the viewing (reflected) direction.
10
Q
BRDF properties
A
11
Q
BRDF simplification in CG
A
12
Q
A
