"Nathan Kopp" wrote:
> An likely alternative would be to have the last two scenes:
>     up y   right x*2
> and
>     up 0.5*y    right x
> be equivilent.
>
> That would better mimic the behavior of the perspective camera,
> where these two cameras would be equivilent.

That is *not* true! Using those two variations with the perspective camera
produces different results. In fact the perspective images in the comparison
image I made were rendered doing just that and as you can see, they differ.

The reason of your misconception probably is that they will produce
equivalent results if the angle keyword is used after the up and right
vectors are specified. When the angle is specified the lengths of the up and
right vectors are adjusted internally to match the angle. But it is not
required to specify the angle, and if it isn't specified, the lengths of the
up and right vectors do make a difference!

I already mentioned the angle keyword in my original post:

"Note that just like in the other camera types, specifying the angle should
of course adjust the horizontal angle while still maintaining the aspect
ratio. The black border should not be affected by the angle though, but only
be controlled with the up and right vectors."

> This provides better consistency across camera types

On the contrary.

> though it does sacrifice some flexibility.

I still think my suggestion is the best one. It's consistent *and* flexible.

> The desired effect (a zoomed-in view of the fisheye lens) could
> be achieved, though, by using POV's partial-render capibilities.

An extremely clumsy solution, especially for animations.

I would appreciate if you would do reread my original message and then tell
me what's wrong with it.

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:    http://rsj.mobilixnet.dk (updated June 26)
POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk

Post a reply to this message