Thorsten Froehlich <tho### [at] trfde> wrote:
: POV-ray on the other hand (for obvious reasons) will determine a
: middle value for both the color and the alpha-channel, which in turn is
: fixed by saying the background is always black.

  Uh, I don't think this is how it does it. That was how 3.1 did it (if the
background was black). The color of pixels which are antialiased against the
background do not use the background color at all. If there's an object which
is completely <0,0,1> (and we make it so that it doesn't change due to
illumination, eg. with ambient 1), then the edge pixels will be completely
<0,0,1> and they will not be faded to black. Only the alpha channel is changed
in the antialiased pixels.
  If POV-Ray did use black as the "background color" when calculating
antialiasing, then the borders would fade to black. This is what 3.1 did, and
it was wrong, and consecuently fixed in 3.5.

-- 
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -

Post a reply to this message