OpenGL OpenGL Lighting and Materials 2

Question 1

Which OpenGL fixed-function call is used to set material properties used in lighting calculations?

Accepted Answer

glMaterialfv()

Answer

glColorMaterial()

Answer

glSetMaterial()

Answer

glMaterial4f()

Question 2

Which GL_MATERIAL parameter controls the color of light a surface appears to emit on its own?

Accepted Answer

GL_EMISSION

Answer

GL_AMBIENT

Answer

GL_DIFFUSE

Answer

GL_SPECULAR

Question 3

What does enabling GL_COLOR_MATERIAL allow in OpenGL?

Accepted Answer

Tracking the current glColor value to automatically set material properties

Answer

Using textures as material color inputs

Answer

Setting multiple material colors simultaneously

Answer

Applying vertex colors to light source definitions

Question 4

Phong shading interpolates normals per-fragment and produces smoother highlights than which shading alternative?

Accepted Answer

Gouraud shading

Answer

Flat shading

Answer

Toon shading

Answer

Wireframe shading

Question 5

What is the primary purpose of surface normal vectors in OpenGL lighting calculations?

Accepted Answer

They determine how light reflects off the surface

Answer

They define texture coordinates for the surface

Answer

They specify the material color

Answer

They control surface transparency

Question 6

In GLSL, which built-in function is most commonly used to ensure a vector has unit length before lighting calculations?

Accepted Answer

normalize()

Answer

length()

Answer

dot()

Answer

cross()

Question 7

A GL_SHININESS (specular exponent) value of 128 compared to a value of 1 produces which result?

Accepted Answer

A smaller, sharper specular highlight

Answer

A larger, softer specular highlight

Answer

No visible specular highlight

Answer

A wider colored highlight