gregjohn wrote:
> Warp <war### [at] tagpovrayorg> wrote:
>>   So my question stands: Why can't you do the exact same thing with a
>> povray-generated image as you would do with a photo?
>>
> 
> 
> I have published products at zazzle.com where I have povray generate the white
> border around the image. Some of these are 1:1, some are 2:1.  It soon becomes
> a labor-saving device when you generate 100 of these products. Before you call
> me petty, I've sold about a dozen of them.
> 
> If the docs were to empower someone to understand the camera, none of this
> discussion would be necessary-- it wouldn't have been started by me! :)  The
> docs fail because they don't teach someone how to create an object that
> precisely covers the screen, regardless of pixel aspect ratio or camera angle.
> Once I figured out how to do it, I wondered if it were a cleanly written
> algorithm. 4:3 is the tripping point.
> 
> One thing that troubles me in this discussion is the concept
> that there are petty uses of povray, that povray is only for certain noble
> tasks.

That has nothing to do with it.  It's not about the ultimate intended 
purpose of the image; its about making the image display correctly.

Changing the aspect ratio of an image can cause serious problems because 
of either cutting out portions of the image, or displaying objects / 
textures that weren't meant to be "on camera."

> Don't worry about anything that could also be done by mouse-dragging in
> photoshop (like cropping to get certain aspect ratios-- imagine doing THAT for
> a 2000-frame animation!!!)

It's not about what's easy to do in Photoshop; it's about what's easy to 
do, period.  In this case, adjusting an image for different aspect 
ratios has two possible solutions: Letterbox it (ie just leave it 
alone), or crop it (which is a solved problem when you use other tools 
like Photoshop or the GIMP).

-- 
Chambers

Post a reply to this message