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24 Nov 2024 17:55:14 EST (-0500)
  Transparency one way only (Message 1 to 5 of 5)  
From: Pahidla
Subject: Transparency one way only
Date: 11 Oct 2007 16:10:01
Message: <web.470e826a61c90da3ccd3f470@news.povray.org>
Hi,

Working on a model of a room and somtimes I would like to take a step back
to see more of the room, but then of course walls (povray boxes) get in the
way. Is there a way to make an object, such as a box, transparent but only
if one looks outside in, i.e. from one direction.

Many thanks in advance,

Pahidla


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From: St 
Subject: Re: Transparency one way only
Date: 11 Oct 2007 16:21:51
Message: <470e85df$1@news.povray.org>
"Pahidla" <dol### [at] yahoocom> wrote in message 
news:web.470e826a61c90da3ccd3f470@news.povray.org...
> Hi,
>
> Working on a model of a room and somtimes I would like to take a step back
> to see more of the room, but then of course walls (povray boxes) get in 
> the
> way. Is there a way to make an object, such as a box, transparent but only
> if one looks outside in, i.e. from one direction.

    Hi Pahidla

     As far as I know, no, there isn't a way to do this. What you can do 
however, is to give your boxes, (walls), a 'no_image' statement in your 
texture, like below, and then pan back out:

    OBJECT {
    [OBJECT_ITEMS...]
    no_image
      }

     You may also want to use 'no_reflection' and 'no_shadow' if you so 
wish.

     See: http://www.povray.org/documentation/view/3.6.1/328/


     ~Steve~




>
> Many thanks in advance,
>
> Pahidla
>
>


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From: Warp
Subject: Re: Transparency one way only
Date: 11 Oct 2007 16:26:02
Message: <470e86da@news.povray.org>
Pahidla <dol### [at] yahoocom> wrote:
> Working on a model of a room and somtimes I would like to take a step back
> to see more of the room, but then of course walls (povray boxes) get in the
> way. Is there a way to make an object, such as a box, transparent but only
> if one looks outside in, i.e. from one direction.

  Using "no_image" in the wall you want to "remove", as suggested, is a
good way.

  Another possibility, if your wall is not a box but a planar surface
(eg. created as a plane or as a polygon) is that you can give it an
interior_texture besides the regular texture. This way you can make
one side of the wall transparent while the other is opaque.

-- 
                                                          - Warp


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From: Le Forgeron
Subject: Re: Transparency one way only
Date: 11 Oct 2007 16:26:46
Message: <470e8706$1@news.povray.org>
Le 11.10.2007 22:07, Pahidla nous fit lire :
> Hi,
> 
> Working on a model of a room and somtimes I would like to take a step back
> to see more of the room, but then of course walls (povray boxes) get in the
> way. Is there a way to make an object, such as a box, transparent but only
> if one looks outside in, i.e. from one direction.
> 
> Many thanks in advance,

You need a patch to do that.
A long time ago, when povray license was understandable, I did that
patch... for 3.1g
it was easy, just a kind of CSG construct (think union) which filter
in All_..._Intersections so that the dot product of the normal and
ray had to be positif to keep a child's intersection.

Works fine... box, cone, sphere, all only showing their inner side,
never their outer side, even in mirror!

Now, if someone can explain how to distribute such patch within the
3.5/3.6/3.7 license, please be my guest and I might consider do that
again.


-- 
The superior man understands what is right;
the inferior man understands what will sell.
-- Confucius


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From: Warp
Subject: Re: Transparency one way only
Date: 11 Oct 2007 17:15:08
Message: <470e925c@news.povray.org>
Le Forgeron <jgr### [at] freefr> wrote:
> You need a patch to do that.

  No you don't.

-- 
                                                          - Warp


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