clipka <nomail@nomail> wrote:
>   Secondly, the way that objects are blended with the background has changed.
>   Previously the color of the background was not taken into account when
>   calculating effects of transmission through translucent objects when +ua is
>   in effect (i.e. where the background could otherwise have been seen through
>   the object). Now, however, the background color is taken into account, even
>   if it is not otherwise visible. (In other words, blending is performed in the
>   same way regardless of the presence of background transparency).

  As I wrote in my original post, I still very strongly protest against
this decision.

  This is how POV-Ray 3.1 (and maybe 3.5, I don't remember) worked, and
it was flawed. It made rendering images with a transparent background
mostly useless.

  It was specifically changed for 3.5 or 3.6 (I don't remember which) to
fix this flaw. You *don't* want the background color to be taken into
account when rendering against a completely transparent background. This
makes it useful to render with transparent background because now the
resulting image can be used to blend it with something else in third-party
programs (such as image editors or web browsers).

  Now in 3.7 this has been reverted to the old, flawed behavior, and now
we once again have undesired background color blended in with the
semi-transparent pixels, ruining the image and making it mostly useless.

  3.6 worked correctly (and not only with antialiasing but also with
semi-transparent objects and media). The reverted behavior in 3.7 is
flawed and has made the results useless once again.

  I can't understand why this was reverted. Maybe the reason for the 3.6
behavior has been forgotten?

-- 
                                                          - Warp

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