Light

Question 1

What is Lambertian reflection?

Answer 1

Lambertian reflectors spread light equally in all directions.

Question 2

What is the equation of Light intensity of Lambertian reflection?

Answer 2

Intensity = Kd * Id * N.L

Question 3

What do the values in the light intensity equation for Lambertian reflection stand for?

Answer 3

Kd = reflectance coefficient
N = Surface normal
L = light vector
Id = Light intensity (3D Vector , rgb)

Question 4

What is the Ambient reflection equation?

Answer 4

I = I_a * K_a

Question 5

What do the values in the ambient reflection equation stand for?

Answer 5

I = Pixel intensity
I_a = ambient light intensity
K_a = ambient reflection coefficient of the surface

Question 6

What is ambient reflection?

Answer 6

A approximation for the contribution of indirect lighting

Question 7

What is diffuse refelction?

Answer 7

Light is reflected in all directions randomly

Question 8

What is specular reflection?

Answer 8

Light is reflected in one focused direction like a mirror

Question 9

How do you normalise a vector (dx, dy, dz)?

Answer 9

Find its length
l = sqrt(dx^2 + dy^2 +dz^2)

Question 10

What is the surface normal equation of a sphere?

Answer 10

n = p - c_s

Question 11

What is the diffuse term equation?

Answer 11

I_Pixel,c = K_d,c * I_Light,c * n · l
n = normalised surface normal
l = normalised vector light source