OpenGL OpenGL Lighting and Materials

Question 1

In OpenGL's Phong lighting model, which component represents light scattered equally in all directions regardless of viewing angle?

Accepted Answer

Ambient

Answer

Specular

Answer

Diffuse

Answer

Emissive

Question 2

Which OpenGL fixed-function call correctly sets the position of a light source?

Accepted Answer

glLightfv(GL_LIGHT0, GL_POSITION, pos)

Answer

glSetLight(GL_LIGHT0, pos)

Answer

glLightPosition(GL_LIGHT0, pos)

Answer

glBindLight(GL_LIGHT0, pos)

Question 3

In the Phong reflection model, the specular component is determined by which pair of vectors?

Accepted Answer

View direction and reflection vector

Answer

Light direction and surface normal only

Answer

Eye position and light position only

Answer

Surface tangent and bitangent

Question 4

What does the GL_SHININESS material parameter control in OpenGL's legacy lighting model?

Accepted Answer

The size and sharpness of specular highlights

Answer

The brightness of the ambient light

Answer

The diffuse reflectivity of the surface

Answer

The number of active light sources

Question 5

What is the maximum number of light sources supported by OpenGL's fixed-function pipeline (GL_MAX_LIGHTS)?

Accepted Answer

8

Answer

4

Answer

16

Answer

32

Question 6

Which lighting components require correctly defined surface normal vectors to produce accurate results?

Accepted Answer

Both diffuse and specular

Answer

Ambient only

Answer

Emissive only

Answer

Neither diffuse nor specular

Question 7

In OpenGL's legacy lighting, what does enabling GL_LIGHT_MODEL_TWO_SIDE accomplish?

Accepted Answer

Performs lighting calculations for both front and back faces of polygons

Answer

Enables two light sources simultaneously

Answer

Enables two-sided texture mapping

Answer

Creates shadow effects on both sides of a surface