Practice Problems – 7/23/2002

Making Art with Computers

Run POV-Ray on the scene file “axes.pov” and you will see something that looks like the following.

This scene shows three axes, each with five little arrows. The red arrows are for the X-axis, the green arrows are for the Y-axis, and the blue arrows are for the Z-axis. Each arrow is one unit long, which means that the three axes span a 5x5x5 cube. The definition for these axes is at the bottom of axes.pov, and you may ignore it.

Also in this scene is a small sphere sitting at location <2, 1, 0>. The definition for this sphere appears at the top of axes.pov, and your task will be to move this sphere by changing the vector <2, 1, 0>.

1) Change the location of the sphere to the values shown, re-render the scene, and draw what you see in the axes provided.

<0, 0, 0> <1, 0, 0> <2, 0, 0>

<0, 1, 0> <0, 0, 1> <1, 1, 0>

<1, 1, 1> <-1, 0, 0> <0, 0, -2>

2) What values must you enter for this vector in order to get the following pictures?

< , , > < , , > < , , >

< , , > < , , > < , , >