In article <3beaaf3a@news.povray.org> , Warp <war### [at] tagpovrayorg>  wrote:

>  When I render the example scene without +ua, all parts of the the text is
> antialiased equally.
>   If I render it with +ua (and antialiasing method 1), then the part of the
> text which has only background behind it doesn't get antialiased (while the
> part which has the boxes behind does). The preview of POV-Ray shows clearly
> this and when I open the resulting image with Gimp, it is identical (that is,
> the edges really aren't antialiased in those parts).
>
>   I'm using the unix version (yes, it supports preview taking into account
> the alpha channel, as the Windows version does), but I suppose that the
Windows
> version works in the same way (I suppose that the original poster is using
> that).
>
>   However, I think the problem seems to be somewhere else. I tried putting
> another black object in the image (a cylinder) and it didn't get antialiased
in
> the lower half of the image either.
>   It seems to me that the color of the objects has something to do with this.
> If I make the cylinder and the text red, then they get antialiased.
>
>   Could it perhaps be that the antialiasing routine thinks that the background
> is black and thus doesn't perform antialiasing with black objects?
>   This is specially curious since the background is specifically set to white.
> Put perhaps the +ua has some effect here.
>   It's also curious why it works with +am2.

These two images show the scene rendered and the preview with and without
alpha-channel display on Macs.  The the thread in povray.beta-test for
details.

    Thorsten


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

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

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Attachments:
Download 'aa.png' (37 KB) Download 'noaa.png' (33 KB) Download 'us-ascii' (0 KB)

Preview of image 'aa.png'

Preview of image 'noaa.png'

This is a partial snapshot of the winpov preview window (which has been
maximized to show the pixels more clearly). The behaviour is exactly the same
as in the unix version.
  And no, it's not something with the preview. When opening the image with
another program (eg. Gimp), the result is identical to that.

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Attachments:
Download 'snapshot.png' (8 KB)

Preview of image 'snapshot.png'

In article <3beadbc2@news.povray.org> , Warp <war### [at] tagpovrayorg>  wrote:

>   This is a partial snapshot of the winpov preview window (which has been
> maximized to show the pixels more clearly). The behaviour is exactly the same
> as in the unix version.
>   And no, it's not something with the preview. When opening the image with
> another program (eg. Gimp), the result is identical to that.

I see.  I finally was able to reproduce your problem.  There is indeed
something very wrong with the alpha channel output.  The Mac version allows
to view the alpha channel even if POV-ray does not explicitly outout one.
When activating alpha channel output the whole output is suddenly screwed
up.  Obviously this is not right, so i can confirm this is a bug - alpha
channel output is completely broken.

    Thorsten

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

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

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> These two images show the scene rendered and the preview with and without
> alpha-channel display on Macs.  The the thread in povray.beta-test for
> details.

I get the same results as Warp does, while I expected to see something like
yours.

Which antialias method have you used to produce these images?

Anyway it seems from the answers exchange between you and Warp in
povray.beta-test that there's something wrong and the problem is being
tackled on.
It seems I've made a useful bug report.

Keep up with your good work!

Alessandro

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