CS 184 – Computer Graphics
Midterm 1
1. Answer True/False: (1 point each)
Each of the three types of color receptors in the eye is sensitive to a single frequency of
light.
A shear transformation can be decomposed into a series of rotations and scale
transformations.
Homogeneous coordinates are useful because 4D spaces include imaginary vectors.
Linear perspective projection keeps straight lines straight.
Every orthonormal matrix defines a rotation.
Surface shading helps reveal the shape of objects.
Z buffers may suffer from quantization errors.
Rotation about an arbitrary axis requires three separate transformations matrices.
The color of some objects result from wave interference.
2. A perspective has its center of projection at origin and its image plane is defined by
z=1.
2A) what set of lines vanish at the point (2, -1, 1)? (5 points)
2B) Which lines do not vanish at a finite point? (3 points)
3. EXTRA CREDIT QUESTION: Which of the following are NOT valid perspective
camera matrices? (place an X over the ones that are not) (1 point each)
42
31
8900
9.7100
0010
0001
2100
1100
0011
0011
1000
2000
0010
0001
−
−
For each one that you crossed out, concisely indicate why it is not valid. (3 points)
4. Draw the polygon that will result when this polygon is clipped against the boundary
shown in the order when using the algorithm discussed inc lass, the Sutherland-Hodgman
