In article <40b72edf$1@news.povray.org> , "Gilles Tran" <tra### [at] inapginrafr>
wrote:
> Uh? I'm not sure I understand why this is a "plague"... The stretch/squeeze
> issue is such a common headache for newcomers that it made its way into FAQ
> 9.1.2.4, which is the primary source of the image_width/image_height trick.
> Hey, for a couple of years in the pre-internet days (no peer support then) I
> rotated all my vertical scenes to render then at 800*600, so I'm talking
> about "real" headaches... As far as I'm concerned, automatic aspect ratio
> should have been the default setting (instead of 4/3) because it's extremely
> practical and something less to worry about. The FAQ says that the current
> behavior is necessary because of the possibility of non-square pixels

The drawbacks have been discussed in this thread:
<http://news.povray.org/*/thread/%3Cslrnc079it.ntq.cera%40queen.mcs.drexel.e
du%3E/>

The summary is that for new users image_width/image_height does more harm
than good as it is not really easy to predict how it behaves.  In particular
Warp gave a good summary of all the problems related to this.

> Are there other
> common circumstances (video output?) where having square pixels by default
> would be problem?

Apart from DV and fullscreen DVD video and most video output systems
available, which are non-square, DVD widescreen is heavily stretched - the
compressed video is always 720 pixels in width and 480 (NTSC) or 576 (PAL)
in height. And there are also non-square pixels with 1280*1024 on a CRT
monitor.

    Thorsten

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

Visit POV-Ray on the web: http://mac.povray.org

Post a reply to this message