"Nathan Kopp" wrote:
> Alpha channel support has been greatly improved in POV 3.5,
> but you need to keep things within appropriate ranges or
> you will get strange results.

Let me tell a bit about the new design.

The alpha channel stores a transparency value for each pixel, just like
there is also stored a value for red green and blue light for each pixel. In
POV-Ray 3.5 when the alpha channel is turned on, all areas of the image
where the background is partly or fully visible will be partly or fully
transparent. Refractions of the background will also be transparent, but not
reflections.

The philosophy of the alpha channel feature in POV-Ray 3.5 is that the
background color should not be present in the color of the image when the
alpha channel is used. Instead, the amount of visible background is kept in
the alpha and *only* in the alpha channel. That ensures that images look
correct when viewed with the alpha channel.

However, it also means that images don't look right when they're viewed
without the alpha channel. POV-Ray itself doesn't support the alpha channel
in the render window, so images where the alpha channel is used may look
strange. The images need to be viewed in an image viewer that supports the
alpha channel, and in some of those programs you need to do something
special to turn on the transparency.

I suggest you have a look and see for yourself!

BTW, I was just a pre-beta tester and I do not speak for the POV-Team, just
from my own experiences.

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:    http://rsj.mobilixnet.dk (updated June 26)
POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk

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