POV-Ray : Newsgroups : povray.beta-test.binaries : mirrors should not reflect shadows Server Time
31 Oct 2024 19:17:53 EDT (-0400)
  mirrors should not reflect shadows (Message 1 to 9 of 9)  
From: Bruno Gimeno
Subject: mirrors should not reflect shadows
Date: 25 May 2002 01:30:30
Message: <3cef2176@news.povray.org>
solutions?


larger image at:
http://usuarios.lycos.es/game2413/galeria/Untitled800x600.jpg

Bruno Gimeno
 -- solo tendreis mi ordenador --
-- cuando me arranqueis el teclado --
   -- de mis frios dedos muertos --


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From: Warp
Subject: Re: mirrors should not reflect shadows
Date: 25 May 2002 07:20:54
Message: <3cef7396@news.povray.org>
Bruno Gimeno <apl### [at] spambillg8jazzfreecom> wrote:
> solutions?

  Thanks for not giving any details about what you want to achieve and
what's the image about. This really helps us giving you the answer you want.

-- 
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -


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From: Rune
Subject: Re: mirrors should not reflect shadows
Date: 25 May 2002 09:38:15
Message: <3cef93c7$1@news.povray.org>
Warp wrote:
>   Thanks for not giving any details about what you
> want to achieve and what's the image about. This
> really helps us giving you the answer you want.

Well, I find it quite obvious that he would like to know a way to avoid
the shadow of the red ball to show up in the mirror, since the red ball
itself is not shown in the mirror due to no_reflection.

I don't know if it's an appropriate post in this group though.

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:  http://rsj.mobilixnet.dk (updated May 20)
POV-Ray Users: http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Ring:  http://webring.povray.co.uk


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From: Bruno Gimeno
Subject: Re: mirrors should not reflect shadows
Date: 25 May 2002 19:38:18
Message: <3cf0206a$1@news.povray.org>
> Well, I find it quite obvious that he would like to know a way to avoid
> the shadow of the red ball to show up in the mirror, since the red ball
> itself is not shown in the mirror due to no_reflection.
>
> I don't know if it's an appropriate post in this group though.
>
> Rune
>

In first place, my but humble excuses for sending an incomplete message.
I'm sorry, but it must have sent in a moment in which the hurries had not
urgeed me so much.

Yes, Rune, the problem that I want to indicate is about avoiding the shadow
of an object
reflected "within the mirror"; and analogous avoiding that the shade of an
object marked
with "no_image" shows itself  "outside the mirror".

It is not the appropiate group to ask this subject?
I Though that would be the most suitable, treating about a new function of
Pov-ray 3,5,
that in my opinion, presents a design failure.  or not?

Thanks beforehand to listen to me and please,
understand that I translate this message using several translators online,
my level of english does not allow me to write with the sufficient clarity



En primer lugar, mis mas humildes excusas por enviar un mensaje incompleto.
lo siento, pero debiera haberlo enviado en un momento en el que las prisas
no me hubieran acuciado tanto.


muestre
la sombra de un objeto reflejado "dentro del espejo" y analogamente, el
evitar
que la sombra de un objeto marcado con "no_image" se muestre "fuera del
espejo".



3.5, que a


Gracias de antemano por escucharme y por favor, comprended
que traduzco este mensaje usando varios traductores on-line, mi nivel de
ingles no me permite escribir con la suficiente claridad


-- Bruno Gimeno --------------------
-- solo tendreis mi ordenador -------
-- cuando me arranqueis el teclado --
-- de mis frios dedos muertos -------


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From: bob h
Subject: Re: mirrors should not reflect shadows
Date: 26 May 2002 02:45:42
Message: <3cf08496@news.povray.org>
If I may, I believe the usual method is to post text about questionable
behavior of 3.5 beta in the povray.beta-test group and then also place any
relevant binary files here in this group, directing to (telling of) each of
those postings. However, in this case you could ask such a thing in
povray.general. And yet, if you have strong suspicions it is a "bug" then by
all means posting to povray.beta-test first and foremost is probably
perfectly acceptable.

Well enough chatter, back to the topic of discussion. :-)

Add no_shadow to the red sphere. I do not know for certain if this was ever
done differently before, i.e. the shadow disappearing along with the
reflection. The three things that seem related here of course are: no_image,
no_reflection and no_shadow. Any combination of those "object modifiers" can
be used to get what you seem to have been trying.

Hope this has been some help.

bob h


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From: Rune
Subject: Re: mirrors should not reflect shadows
Date: 26 May 2002 05:47:59
Message: <3cf0af4f$1@news.povray.org>
bob h wrote:
> Add no_shadow to the red sphere.

Err, that would also remove the shadow from the red sphere itself, not
just the reflection of the shadow of the red sphere...

> The three things that seem related here of course are:
> no_image, no_reflection and no_shadow. Any combination
> of those "object modifiers" can be used to get what you
> seem to have been trying.

I don't see how...?

Of course I may have misunderstood what Bruno is trying, but if he
wanted to remove the shadow in the mirror of the red sphere without
removing the shadow of the red sphere itself, I don't know how that's
possible using just those object modifiers.

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:  http://rsj.mobilixnet.dk (updated May 20)
POV-Ray Users: http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Ring:  http://webring.povray.co.uk


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From: bob h
Subject: Re: mirrors reflect shadows test scene
Date: 27 May 2002 04:12:16
Message: <3cf1ea60@news.povray.org>
"Rune" <run### [at] mobilixnetdk> wrote in message
news:3cf0af4f$1@news.povray.org...
>
> Of course I may have misunderstood what Bruno is trying, but if he
> wanted to remove the shadow in the mirror of the red sphere without
> removing the shadow of the red sphere itself, I don't know how that's
> possible using just those object modifiers.

Isn't, I suppose. Just groping in the dark for a solution. I realized the
non-reflected shadow was probably a neccessity but that wasn't mentioned, so
I went ahead and tossed no_shadow into the mix.
 Seems one of those feats requiring some wizardry.  For example a
light_group, already mentioned by someone else I think, involving a second
sphere to cast the false shadow to replace the missing one. Trying that out
just now I didn't get it right, the mirror (and floor) shows the reflected
shadow even though it isn't a part of the group. At least that could
possibly be a bug, if I'm doing this like it should be.

So, if someone cares to double check on this here's what I was using to
attempt Bruno's desired result:


/* Idea: red sphere should have no shadow.
   Sphere should have a shadow on floor
   but not a shadow in mirror.
*/

#version 3.5;

camera {
  location  <2, 2, -4>
  look_at   <1, 0, 1>
  angle 50
}

// original object
light_group {

light_source {
  <-10, 10, -5>, 1.5
}

sphere { // this is removed from mirror
  0, 1
    pigment {
        color red 1
            }
 // no_image
  no_reflection
  no_shadow
}

plane { // floor here, in other group, anywhere... no matter(?)
  y, -1
  pigment { checker rgb 1/3, rgb 2/3 }
}

 global_lights off
}

// fake shadow... still shows up in mirror
light_group {

light_source {
  <-10, 10, -5>, 1.5
}

sphere { // replacment object
  0, 1
    pigment {
        color green 1
            }
  no_image
 // no_reflection
 // no_shadow
}

 global_lights off
}

// global lighting/objects
light_source {
  <-10, 10, -5>, 1.5
}

plane { // mirror... tied only to this light?
  z, 2
  pigment { color rgb .5 }
  finish {
  reflection {<1,1,0>}
  }
}


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From: Bruno Gimeno
Subject: Re: mirrors reflect shadows test scene
Date: 27 May 2002 17:17:32
Message: <3cf2a26c$1@news.povray.org>

news:3cf1ea60@news.povray.org...
> "Rune" <run### [at] mobilixnetdk> wrote in message
> news:3cf0af4f$1@news.povray.org...
> >

my idea was to make something similar to this, whitout using a paint program
http://usuarios.lycos.es/game2413/galeria/untitled5.jpg
(i think it's impossible)

i think that is a failure desing (someone says that is better and easy
with a paint program), read opinions here:
http://news.povray.org/povray.general/24666/173330/#173330

well, if l'harmonieux forgeron have the reason, i should accept that
invisible objects still cast shadows

Bruno Gimeno
solo tendreis mi ordenador
cuando me arranqueis el teclado
de mis frios dedos muertos


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From: bob h
Subject: Re: mirrors reflect shadows test scene
Date: 28 May 2002 04:51:39
Message: <3cf3451b@news.povray.org>
Yes. Makes sense. I was fairly sure I could try that myself and by using
light_group confine the reflected shadow to one place or another. Now I see
it doesn't, not that I can find. Explanation so far seems to be that
mirrored objects ignore light_groups.

bob h


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