ECSE-4750 Computer Graphics, Rensselaer Polytechnic Institute, Midterm Exam, Fall 2014, 9 Oct 2014 4-5:30
NAME: _________________________________ EMAIL:_________________________ RIN:______________
There are six pages with 25 questions, each worth
2 points. Answer every question but 2. You may write FREE
as the answer for two questions (and get the 2 points each).
This exam is closed book: you may use calculators and one 2-sided letter-size note sheet that you brought with you. You may not use computers or communication devices, or share material with other students.
- _____/(2 points) What display technology uses the fact that you see color with less precision than you see brightness?
- _____/2 Processing objects 1-by-1 with a graphics pipeline has a
major advantage and also a major disadvantage. Name them.
- _____/2 You call gl.BufferSubData to do what?
- _____/2 Why does OpenGL contain primitives, like triangle fans,
that are not necessary (since you could draw the triangles
separately)?
- _____/2 Why do we consider color to have three dimensions, such
as RGB? There are an infinite number of visible wavelengths.
- _____/2 What is the event loop?
- _____/2 Use the vector formulation or your intuition to rotate the point
(0,0,2) by 180 degrees about the axis (1,0,0).
- ____/2 You see the expression flatten(points) often in Javascript programs. What does flatten do?
- ____/2 What feature in OpenGL is used to display the closest object when several objects overlap the same pixel?
- ____/2 What's the point of using two color buffers, one to draw into, while the other is being displayed?
- ____/2 Give the 4x4 homogeneous 3D matrix for a uniform scale
by a factor of 2 followed by a translation by (0,0,3).
- _____/2 What's the quaternion representing a rotation of 360 degrees about the axis (1,0,0)?
- _____/2 What does this statement do? gl.uniform1f(thetaLoc, theta);
Also say what theta and thetaLoc are.
- _____/2 When rendering a triangle, you are given various properties at
each vertex, and then need to interpolate them at each pixel inside the
triangle. One such property is position. Name two other properties.
- _____/2 Here is a 3D homogeneous point: (1,2,3,1). What Cartesian point
does it correspond to?
- _____/2 In shaders, what is a uniform variable?
- _____/2 What are the four major components of the OpenGl model as discussed in class?
- _____/2 When using a pipeline to clip a 3D object, how many
stages can be used?
- _____/2 For the default OpenGL camera, where is it and in what direction does it look?
- _____/2 What is the use of the CIE chromaticity diagram?
- _____/2 If i and j are quaternions, simplify i+j as much as possible.
- _____/2 The parametric equation for the plane through the points (1,0,0), (0,1,0), (0,0,0) is:
- _____/2 If a 3x3 rotation matrix has eigenvalues {$1, \frac{1}{2}+\frac{\sqrt{3}}{2}i, \frac{1}{2}-\frac{\sqrt{3}}{2}i $}, then what is the cosine of the rotation angle?
- _____/2 This is a homogeneous 3D translation matrix:
{$\begin{pmatrix} 2&0&0&2\\ 0&2&0&3\\0&0&2&4\\ 0&0&0&2
\end{pmatrix} $}. Use it to translate the homogeneous point
(2,2,2,2) and tell me the Cartesian equivalent of the result.
- _____/2 In the OpenGL pipeline, the Primitive Assembler does
what?
end of exam