The Graphics Pipeline - ANSWER Model, Object/World, Eye, Projection,
NDC, Window
Sketch and label the geometric elements in the Phong illumination model at
point p - ANSWER Normal vector, light vector, view vector, and reflection
vector, theta is the angle between Light and normal, Phi is the angle between the
reflection vector and the view vector which is controlled by the shininess value
In the Phong illumination model what property involves the view's position -
ANSWER Specular
In the Phong illumination model what property involves the surface normal -
ANSWER Defuse and Specular
Sketch the cosine function from -pi to pi and what is the maximum value of the
cosine function? Minimum value? - ANSWER Maximum value is 1,
Minimum value is -1
What is the shininess coefficient in the Phong model? - ANSWER Control the
focus or specular highlight
If a red ball is illuminated by a blue light, what color will the Phong model
render the ball - ANSWER Black, the colors cancel out
What is back face culling? Sketch the idea - ANSWER The user will never see
the back of an object so why render it? Throw away polygons that have an angle
greater than 90 degrees (back facing)
How is the surface normal for s(v, theta) calculated - ANSWER Take the
derivative of the s(v, theta) equation in terms of both v and theta. Then get the
cross product divided by the dot product to get the unit vector
NDC, Window
Sketch and label the geometric elements in the Phong illumination model at
point p - ANSWER Normal vector, light vector, view vector, and reflection
vector, theta is the angle between Light and normal, Phi is the angle between the
reflection vector and the view vector which is controlled by the shininess value
In the Phong illumination model what property involves the view's position -
ANSWER Specular
In the Phong illumination model what property involves the surface normal -
ANSWER Defuse and Specular
Sketch the cosine function from -pi to pi and what is the maximum value of the
cosine function? Minimum value? - ANSWER Maximum value is 1,
Minimum value is -1
What is the shininess coefficient in the Phong model? - ANSWER Control the
focus or specular highlight
If a red ball is illuminated by a blue light, what color will the Phong model
render the ball - ANSWER Black, the colors cancel out
What is back face culling? Sketch the idea - ANSWER The user will never see
the back of an object so why render it? Throw away polygons that have an angle
greater than 90 degrees (back facing)
How is the surface normal for s(v, theta) calculated - ANSWER Take the
derivative of the s(v, theta) equation in terms of both v and theta. Then get the
cross product divided by the dot product to get the unit vector
