POV-Ray : Newsgroups : povray.bugreports : invalid handling of funky Image-Ratio : Re: invalid handling of funky Image-Ratio Server Time
3 Mar 2024 11:39:59 EST (-0500)
  Re: invalid handling of funky Image-Ratio  
From: clipka
Date: 23 Dec 2018 16:08:28
Message: <5c1ff94c$1@news.povray.org>
Am 23.12.2018 um 20:22 schrieb Q0X:
> My intention was actually to render a full HD image with the assumption that it
> scales the height respectively

Well, what should I say?
That assumption is wrong.

POV-Ray dates back to times when square pixels were far from standard. 
As a consequence, you need to specify both logical width /and/ height. 
If you omit any of the two, POV-Ray will use to the respective default 
for that dimension, rather than compute it from the logical aspect ratio 
specified in the scene file.

So you're not observing a bug there, but merely the - in your case 
unexpected - effects of intentional behaviour.


POV-Ray v3.8 (currently in development) can automatically compute the 
physical aspect ratio from the logical width and height presuming square 
pixels (by having the `right` camera parameter default to 
`x*image_width/image_height`), but not the other way round, due to 
limitations of its (current) internal architecture.

(Besides, even if POV-Ray could deduce logical image height from logical 
image width and physical aspect ratio, you would have to specify that 
physical aspect ratio somewhere. Your camera statement says you want an 
image aspect ratio of 1:1. For full HD (16:9), that would have to be 
`right x*16/9`.)


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