Hello,

So I have read through documentation on the camera object in POV-ray and I have
a few questions about how it creates the image plane geometry. From the diagram
in the documentation, it seems the <direction> vector controls the "focal
length" of the camera, where the <location> vector is the focal point. The
<direction> vector can be used to set the angle of view of the camera with its
length. It seems from the documentation's figure that the direction vector does
this by assuming an image plane that is 1 unit by 1 unit. Such that the
following camera:

camera {
  location <0,0,0>
  direction <0,0,0.5>
}

Should make a camera with a field of view of 90 degrees. Now, if I am correct so
far, then Povray will create the <right> and <up> vectors to satisfy the default
aspect ratio. For an output image of 640x480, This would imply that each pixel
(square pixel) will have a side that is (1unit/640) or 0.0016 units/pixel.
However, from other computation that I am doing, it seems I am making an error
with my calculation of the pixel width of the image. Does this seems correct or
am I doing something wrong?

Thanks,
~Carl

Post a reply to this message