When I set output_alpha to on, it sets the whole media container to alpha 255.

What am I doing wrong?

Thanks

--
#macro C(X,Y)cylinder{X*x<X,0,-Y/2>.1}#end#macro U(R,X,Y)intersection{torus{.9
.1}box{-1 0rotate y*R*90}translate<X,0,Y>scale 1-z*.5}#end union{U(0,0,0)U(1,0
,0)U(2,-1,-1)U(1,1,0)U(1,1.5,-3)U(1,2,0)U(3,1,0)U(2,2,0)U(0,3,0)U(3,2,.5)C(.1,
2)C(.8,1)C(.8,-1)C(1.1,1)C(1.9,-1)pigment{rgb 10}rotate x*90translate<-1,0,4>}

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On Tue, 3 Jul 2001 16:16:48 +0200, "Elias Pschernig"
<eli### [at] aonat> wrote:

>When I set output_alpha to on, it sets the whole media container to alpha 255.
>
>What am I doing wrong?

POV's alpha channel only indicates the presence of an object. It is
not affected by transparency nor any interior you give to transparent
objects.


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg

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> POV's alpha channel only indicates the presence of an object. It is
> not affected by transparency nor any interior you give to transparent
> objects.
 
Ok, thanks. (I already suspected something like that after seeing it
behaves the same for standard objects.) If I need output with an alpha
channel, are there any options I have with povray ? I don't like
switching to something else at all of course..

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On Tue, 3 Jul 2001 23:28:43 +0200, "Elias Pschernig"
<eli### [at] aonat> wrote:

>Ok, thanks. (I already suspected something like that after seeing it
>behaves the same for standard objects.) If I need output with an alpha
>channel, are there any options I have with povray ? I don't like
>switching to something else at all of course..

Aside from rendering you media container in black and white and using
that as the alpha channel... I am afraid not much can be done within
POV at this stage. Various techniques can be used to make POV render
all your alpha for you, but I need to know more about your particular
case.


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg

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Peter Popov <pet### [at] vipbg> wrote:
: Aside from rendering you media container in black and white and using
: that as the alpha channel... I am afraid not much can be done within
: POV at this stage.

  AFAIK some work has been/is being done in pov3.5 to make the alpha channel
work better.

-- 
#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 -

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> Aside from rendering you media container in black and white and using
> that as the alpha channel... I am afraid not much can be done within
> POV at this stage. Various techniques can be used to make POV render
> all your alpha for you, but I need to know more about your particular
> case.

It would really have been nice if it was supprted directly. I use it for some
animations with an alpha channel. (They will be used in a game to do some explosion
and light effects.) The black-and-white options would be better than nothing, i could
at least do something like smoke effects with media. (But would have no alpha channel
as well i guess.) Are there any documents with information for the other techniques ?
All i'd need is instead of just r, g and b for every pixel, also a component
specifying how transparent it is over the background.

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