Another important choice to be made is that of the
field of view of the camera. The size of this field describes
the angles between the left and right sides and top and bottom sides
of the frustum.
- <#4656#><#4656#>
- <#1214#>fov<#1214#> <#1215#>hfov<#1215#> [<#1216#>vfov<#1216#>]
Specify
the horizontal and vertical field of view, in degrees.
The default horizontal field of view is 45 degrees.
If <#241#>vfov<#241#> is omitted, as is the general practice,
the vertical field of view is computed using the horizontal
field of view, the output image resolution, and the assumption
that a pixel samples a square area. Thus,
the values passed via the
<#242#>screen<#242#> keyword define the shape of the final image.
If you are
displaying on a non-square pixeled device,
you must set the vertical field of view
to compensate for the ``squashing'' that will result.