>"Warp" <war### [at] tagpovrayorg> wrote
>   That's actually not really true.
>
Of course you are right in some respects, but it is
right because it does what I expect it to do and it is
what I want. The scene stays the same but the
aspect ratio changes. More on the sides or top is
the way I would want to change aspect ratio. A
panoramic aspect ratio does show a lot more of the
secene in the horizontal.



>   If you change the aspect ratio of the rendering resolution and the
> camera adjusts automatically to that using "right
image_width/image_height",
> the image will be adjusted vertically so that part of the image from the
> up and bottom sides will go out of the image (if changing to a wider
> aspect ratio) or some extra scenery will appear at the top and the
> bottom (if changing to a narrower aspect ratio).

Yeah, that is usually what I want. I wouldn't want the x or y dimensions
distorted.

>   An additional drawback is that if you really want to keep the 4:3 aspect
> ratio even though you are rendering with a resolution having a different
> aspect ratio (eg. a 320x400 image for the Windows startup image), your
> automatic camera setting will produce the undesired effect (ie. the aspect
> ratio of the image is not kept to 4:3), thus you need to edit the camera
> parameters again.

The few times I've made custom Windows start up images I have rendered
them in 4:3 aspect ratio then compressed them to half width in Paint Shop
Pro.
Guess one could do it directly with the camera statement. Probably better to
do it that way. Yet that is not what is meant by aspect ratio, at least not
as
it is used in film. It refers to simply the ratio of width to height of the
edges of
the image. The sort of compression represented by a 320x400 windows
startup image is analogous to "anamorphic" compression in the film industry,
which allows wide screen (wide aspect ratio) movies to be printed on
standard
35mm width film, then stretched by the projector lens to cover the wide
aspect
ratio.

HB

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Harold <bai### [at] 3dculturecom> wrote:
> >   If you change the aspect ratio of the rendering resolution and the
> > camera adjusts automatically to that using "right
> image_width/image_height",
> > the image will be adjusted vertically so that part of the image from the
> > up and bottom sides will go out of the image (if changing to a wider
> > aspect ratio) or some extra scenery will appear at the top and the
> > bottom (if changing to a narrower aspect ratio).

> Yeah, that is usually what I want. I wouldn't want the x or y dimensions
> distorted.

  That was not my point. Read it again.

> The few times I've made custom Windows start up images I have rendered
> them in 4:3 aspect ratio then compressed them to half width in Paint Shop
> Pro.

  The problem is that the 320x400 resolution does not have a 2:3 aspect ratio,
so half-width won't do it. (The aspect ratio is 4:5 to be exact.)

> Guess one could do it directly with the camera statement.

  No, you don't need to do anything abnormal with the camera statement.
Just define a default 4:3 camera (ie. you don't need to specify any
'right' vector) and render at 320x400 and you'll get an image which
looks ok when viewed with your monitor set to 320x400 resolution (as
it is when the Windows startup image is shown).


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