POV-Ray : Newsgroups : povray.newusers : Help on transparency Server Time
26 Nov 2024 23:39:26 EST (-0500)
  Help on transparency (Message 1 to 4 of 4)  
From: Dave
Subject: Help on transparency
Date: 20 Aug 2003 04:50:31
Message: <3f433657$1@news.povray.org>
Hi,

I'm trying to create a moving gif with a transparent background to put into
a web page.

I can create what I want as a png file which, in PovRay, looks like a
transparent background (ie the grey-white check).  However, if I open the
images in Photoshop, or insert into a web page, the background is black.

I have used

background { color rgbf <0,0,0,1> }

in the .pov file and

+UA

in the .ini file.

Any ideas anyone?


Dave


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From: JC (Exether)
Subject: Re: Help on transparency
Date: 20 Aug 2003 07:13:34
Message: <3f4357de$1@news.povray.org>
From my experience all imaging tools don't handle png's transparency 
very well. I'm a bit supprised Photoshop doesn't though, but you can try 
with Gimp which supports it and save your image as gif or use ImageMagik 
convert utility.

Into web pages, it depends on the browser, IE doesn't do transparency 
(new versions might though), but Mozilla handles it.

Also, the background color that you set doesn't matter since you put the 
+UA option.

JC

Dave wrote:
> Hi,
> 
> I'm trying to create a moving gif with a transparent background to put into
> a web page.
> 
> I can create what I want as a png file which, in PovRay, looks like a
> transparent background (ie the grey-white check).  However, if I open the
> images in Photoshop, or insert into a web page, the background is black.
> 
> I have used
> 
> background { color rgbf <0,0,0,1> }
> 
> in the .pov file and
> 
> +UA
> 
> in the .ini file.
> 
> Any ideas anyone?
> 
> 
> Dave
> 
>


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From: Hughes, B 
Subject: Re: Help on transparency
Date: 20 Aug 2003 08:16:54
Message: <3f4366b6@news.povray.org>
"Dave" <dav### [at] btinternetcom> wrote in message
news:3f433657$1@news.povray.org...
>
> I'm trying to create a moving gif with a transparent background to put
into
> a web page.

Wish I could help with that program but I have never used Photoshop. I'm a
long time Paint Shop Pro user and version 8 does okay with the transparency
when saving to GIF as long as it is a single solid color to begin with.

Animation Shop 3 (comes with PSP 8) will retain the transparency while no
modifications or optimizations are made. However, if the transparency is
graduated, has mixed colors or is subjected to effects, it loses the
transparency. If it can be done I don't know how, but I'd expect PS to be
superior in all respects so maybe there's hope.

If all you want is cutaway parts to be removed, for web page backgrounds to
show through, it ought to be possible. So check into settings for
transparent canvas or background in the properties or preferences.

Bob H.


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From: Mike Williams
Subject: Re: Help on transparency
Date: 21 Aug 2003 01:50:04
Message: <iiqk2EASfER$Ewr9@econym.demon.co.uk>
Wasn't it Hughes, B. who wrote:
>"Dave" <dav### [at] btinternetcom> wrote in message
>news:3f433657$1@news.povray.org...
>>
>> I'm trying to create a moving gif with a transparent background to put
>into
>> a web page.
>
>Wish I could help with that program but I have never used Photoshop. I'm a
>long time Paint Shop Pro user and version 8 does okay with the transparency
>when saving to GIF as long as it is a single solid color to begin with.

I'm also a long time PSP user, but I'd guess that the problem is at the
PNG end. PSP8 would do the job cleanly, but PSP7 the PNG alpha mask
wasn't automatically applied to the image transparency. You had to
explicitly load it from the alpha channel into the transparency mask.
Many programs seem to have problems with PNG transparency (in particular
all versions of Internet Explorer and versions of Nescape Navigator
prior to v6.02) so perhaps Dave is using a version of PS that doesn't
handle PNG transparency properly.

-- 
Mike Williams
Gentleman of Leisure


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