Hello,

I've tryed but can't get POV-Ray rendering images with alpha channel on the
resulting image. I tried using the comand lines:
"+UA","+UAFN" and a few others but still no alpha on the final render. Can
anybody give me some help?n Thanks

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MadKairon <nomail@nomail> wrote:
> Hello,

> I've tryed but can't get POV-Ray rendering images with alpha channel on the
> resulting image. I tried using the comand lines:
> "+UA","+UAFN" and a few others but still no alpha on the final render. Can
> anybody give me some help?n Thanks

  How about "+ua +fn" instead?

  And the (empty) background must be directly visible in the rendered image
for there to be any transparency in the image.

-- 
                                                          - Warp

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nope, I also tried +ua +fn32. Now I get at least the alpha channel but no
transparency information. On GIMP alpha channel is just white. The scene is
basically an object and the rest is all background, not even sky sphere is set.

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wait... I solved it, I was using radiosity and setting a background color to
affect how my object looked like. This is too bad, I really needed that
background color, it's not the same effect without it even if I still use
radiosity and some ambient lights. Gonna try to render it without the
background and then use that alpha channel for the other image.

Post a reply to this message

"MadKairon" <nomail@nomail> wrote:
> I've tryed but can't get POV-Ray rendering images with alpha channel on the
> resulting image. I tried using the comand lines:
> "+UA","+UAFN" and a few others but still no alpha on the final render. Can
> anybody give me some help?n Thanks

the correct thing should be:

  +UA +FN

(the second parameter selecting the PNG so you get a file format that does
support the alpha channel; note that POV-Ray does *not* support concatenating
of command line switches.)

Make sure you're not using a sky_sphere - or any other "sky object" of course.

Post a reply to this message

"MadKairon" <nomail@nomail> wrote:
> nope, I also tried +ua +fn32. Now I get at least the alpha channel but no
> transparency information. On GIMP alpha channel is just white. The scene is
> basically an object and the rest is all background, not even sky sphere is set.

I'd be surprised if POV-Ray's PNG output would support 32-bit *per channel*.

Please do try "+UA +FN", it should give you a nice standard PNG file with alpha
channel.

Maybe GIMP doesn't support alpha channels with any other bit depth than the
default of 8 bits. Or POV-Ray doesn't.

Post a reply to this message

"MadKairon" <nomail@nomail> wrote:
> wait... I solved it, I was using radiosity and setting a background color to
> affect how my object looked like. This is too bad, I really needed that
> background color, it's not the same effect without it even if I still use
> radiosity and some ambient lights. Gonna try to render it without the
> background and then use that alpha channel for the other image.

Try using a huge sphere with finish { ambient 1 diffuse 0 specular 0 }, and the
no_image keyword.

Post a reply to this message

"clipka" <nomail@nomail> wrote:
> "MadKairon" <nomail@nomail> wrote:
> > wait... I solved it, I was using radiosity and setting a background color to
> > affect how my object looked like. This is too bad, I really needed that
> > background color, it's not the same effect without it even if I still use
> > radiosity and some ambient lights. Gonna try to render it without the
> > background and then use that alpha channel for the other image.
>
> Try using a huge sphere with finish { ambient 1 diffuse 0 specular 0 }, and the
> no_image keyword.

Thanks clipka, that solves it 100%

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