Question: I know how to turn on alpha channels in the rendering prefs, but
they only get saved if I do a "Save As" on the rendered image. The image
file that is automatically saved when I render does not contain the alpha
channel.

Therefore, when I do a batch rendering, the saved images do not have the
alpha channel, even though it was enabled in the settings.


Am I missing something?

Paul

(POV-Ray Mac 3.1.g.r2)

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Paul Kuehn wrote:
> 
> Question: I know how to turn on alpha channels in the rendering prefs, but
> they only get saved if I do a "Save As" on the rendered image. The image
> file that is automatically saved when I render does not contain the alpha
> channel.
> 
> Therefore, when I do a batch rendering, the saved images do not have the
> alpha channel, even though it was enabled in the settings.
> 
> Am I missing something?

Image format? Not all image formats support the alpha channel. Try it
with .png and see what happens (if you are not already).

-- 
Ken Tyler

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Thanks, Ken-

That works.  

Although I was trying with pict, which _does_ support alpha, and it worked
with the manual save, just not the automatic. Wonder why?

Paul


> From: Ken <tyl### [at] pacbellnet>
> Organization: TAG
> Newsgroups: povray.macintosh
> Date: Wed, 23 Jan 2002 18:04:05 -0800
> Subject: Re: Alpha channels in batch renders?
> 
> 
> 
> Paul Kuehn wrote:
>> 
>> Question: I know how to turn on alpha channels in the rendering prefs, but
>> they only get saved if I do a "Save As" on the rendered image. The image
>> file that is automatically saved when I render does not contain the alpha
>> channel.
>> 
>> Therefore, when I do a batch rendering, the saved images do not have the
>> alpha channel, even though it was enabled in the settings.
>> 
>> Am I missing something?
> 
> Image format? Not all image formats support the alpha channel. Try it
> with .png and see what happens (if you are not already).
> 
> -- 
> Ken Tyler

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Paul Kuehn wrote:

> Although I was trying with pict, which _does_ support alpha, and it worked
> with the manual save, just not the automatic. Wonder why?

I really don't know. As a non-MAC user I can only guess that there is
a problem with pict alpha support in the version of POV-Ray that you
are currently using. I am fairly sure that Thorsten will read this
and offer some guidance on this issue.

-- 
Ken Tyler

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"Paul Kuehn" <pku### [at] maccom> schrieb im Newsbeitrag
news:B875ABB1.910A%pku### [at] maccom...
> Although I was trying with pict, which _does_ support alpha, and it worked
> with the manual save, just not the automatic. Wonder why?

Hmm, are you sure you turned it on in the Rener Settings?  Are you using
QuickTiem compression for the picture? What program are you trying to view
it with?

    Thorsten

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Thorsten-

Yes, it's turned on in the Render settings, Compression is _not_ checked.
I'm opening the image in Photoshop. The alpha channel is definitely there
when I manually save the image after rendering is complete, but if I open
the file that was automatically saved upon completion, there is no alpha
channel.

Paul


> Newsgroups: povray.macintosh
> Date: Fri, 25 Jan 2002 10:19:36 +0100
> Subject: Re: Alpha channels in batch renders?
> 
> "Paul Kuehn" <pku### [at] maccom> schrieb im Newsbeitrag
> news:B875ABB1.910A%pku### [at] maccom...
>> Although I was trying with pict, which _does_ support alpha, and it worked
>> with the manual save, just not the automatic. Wonder why?
> 
> Hmm, are you sure you turned it on in the Rener Settings?  Are you using
> QuickTiem compression for the picture? What program are you trying to view
> it with?
> 
> Thorsten
> 
>

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In article <B876EF8A.FBB1%pku### [at] maccom> , Paul Kuehn <pku### [at] maccom>  
wrote:

> Yes, it's turned on in the Render settings, Compression is _not_ checked.
> I'm opening the image in Photoshop. The alpha channel is definitely there
> when I manually save the image after rendering is complete, but if I open
> the file that was automatically saved upon completion, there is no alpha
> channel.

You are right, it turns out there is no alpha channel generated for Pict
images.  Interesting that nobody noticed this in over three years...
So, using batch render you can't get the alpha channel, sorry.

    Thorsten

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

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

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Oh, well... thanks to Ken for the png workaround.

Paul

> From: "Thorsten Froehlich" <tho### [at] trfde>
> Newsgroups: povray.macintosh
> Date: Sat, 26 Jan 2002 12:00:16 +0100
> Subject: Re: Alpha channels in batch renders?
> 
> You are right, it turns out there is no alpha channel generated for Pict
> images.  Interesting that nobody noticed this in over three years...
> So, using batch render you can't get the alpha channel, sorry.
> 
> Thorsten

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