In article <3c30b4c0@news.povray.org> , "Rune" <run### [at] mobilixnetdk>
wrote:

> Specifying the orthographic keyword as the last thing in the camera
> definition has always been a *very* handy feature which meant you didn't
> have to fiddle with the width and height vectors. It's even stated clearly
> in the documentation:
>
> "If you add the orthographic keyword after all other parameters of a
> perspective camera you'll get an orthographic view with the same image area,
> i.e. the size of the image is the same. In this case you needn't specify the
> lengths of the right and up vector because they'll be calculated
> automatically."
>
> The discussed feature change (not bug fix) would be a *major* brake of
> backwards compatibility and would make it much more annoying to work with
> the orthographic camera in general. Please don't cripple the software like
> that! :(

Calm down.  First of all, you can always use the old style, simply by having
version set to 3.1 when specifying the camera. (**Read the next paragraph**)

Second, and more important, all the issues that I know will result out of
the enforced keyword will be worked out.  However, the camera object and the
side effects of individual keyword within camera are *extremely* complex.
As some bug reports have shown, in some cases they are not desired.  As your
report shows, there are also various cases where a specific order matters or
provides a special feature.

So, let me put it this way:  The current change, which will be either in its
current or in a more advanced form be in the next beta does not mean the
feature is locked for 3.5.  It also does not mean it suddenly breaks all
scenes without workaround.  Old scenes do continue to work with a version
setting.

Even more important:  For a future rewrite it is necessary to have
well-behaved features with deterministic rules.  Right now there are a lot
of implicit assumptions when creating a camera.  These will be replaced with
well specified and homogenous rules that will also make the feature easier
to use - as the current docs point out, it is easy to make mistakes when
creating a camera and POV-Ray will not tell you, it will just not work.
This is what will change, no feature will be removed or inaccessible.

    Thorsten

____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

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