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The camera statement describes where and how the camera sees
the scene. It gives x-, y- and z-coordinates to indicate the position of the
camera and what part of the scene it is pointing at. We describe the
coordinates using a three-part vector. A vector is specified by
putting three numeric values between a pair of angle brackets and separating
the values with commas. We add the following camera statement to the
scene.
camera {
location <0, 2, -3>
look_at <0, 1, 2>
}
Briefly, location <0,2,-3> places the camera up two
units and back three units from the center of the ray-tracing universe which
is at <0,0,0>. By default +z is into the screen and -z is back out of
the screen.
Also look_at <0,1,2> rotates the camera to point at the
coordinates <0,1,2>. A point 1 unit up from the origin and 2 units away
from the origin. This makes it 5 units in front of and 1 unit lower than the
camera. The look_at point should be the center of attention of
our image.
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