POV-Ray : Newsgroups : povray.newusers : shadow problem Server Time
6 Sep 2024 08:13:16 EDT (-0400)
  shadow problem (Message 1 to 7 of 7)  
From: zharris
Subject: shadow problem
Date: 1 Dec 1998 01:50:03
Message: <3663919b.0@news.povray.org>
Hi all,
I'm creating my first POV Ray scene, but I struck a snag.
I'm trying to do a greeting card, and have managed to do so with 2 polygons,
and mapping an image to both of them, the problem is the front part of the
card, doesn't cast a shadow onto the back part to give the illusion it is
standing up.
I have tried fidling the Ambient and diffuse with no success.  Is there any
thing else I can try?, or maybe even another way of creating a greeting card
other than using 2 polygons?
thanks in advance
Cheers
Zane


Post a reply to this message

From: Margus Ramst
Subject: Re: shadow problem
Date: 1 Dec 1998 06:21:42
Message: <3663D116.1F443EB7@peak.edu.ee>
Difficult to say what the problem is... Perhaps the light source is
positioned so that the front part doesnt cast a shadow onto the back
part. The keyword "no_shadow" forces objects to be shadowless, perhaps
you used this?
If the scene is not too large, you might post it here.

Margus

zha### [at] galaxycomnetnz wrote:
> 
> Hi all,
> I'm creating my first POV Ray scene, but I struck a snag.
> I'm trying to do a greeting card, and have managed to do so with 2 polygons,
> and mapping an image to both of them, the problem is the front part of the
> card, doesn't cast a shadow onto the back part to give the illusion it is
> standing up.
> I have tried fidling the Ambient and diffuse with no success.  Is there any
> thing else I can try?, or maybe even another way of creating a greeting card
> other than using 2 polygons?
> thanks in advance
> Cheers
> Zane


Post a reply to this message

From: Nieminen Mika
Subject: Re: shadow problem
Date: 1 Dec 1998 11:27:39
Message: <366418fb.0@news.povray.org>
Margus Ramst <mar### [at] peakeduee> wrote:
: Difficult to say what the problem is... Perhaps the light source is
: positioned so that the front part doesnt cast a shadow onto the back
: part. The keyword "no_shadow" forces objects to be shadowless, perhaps
: you used this?

  Another possibility is that the distance between card and the wall is
so long that the shadow is outside the screen.

-- 
main(i){char*_="BdsyFBThhHFBThhHFRz]NFTITQF|DJIFHQhhF";while(i=
*_++)for(;i>1;printf("%s",i-70?i&1?"[]":" ":(i=0,"\n")),i/=2);} /*- Warp. -*/


Post a reply to this message

From: zharris
Subject: Re: shadow problem
Date: 1 Dec 1998 23:31:36
Message: <3664c2a8.0@news.povray.org>
thanks for the info.
here is the file, and the 2 "gifs" I'm using to map onto the card.

Thanks
 Zane


Post a reply to this message


Attachments:
Download 'shadow_prob.zip' (31 KB)

From: zharris
Subject: Re: shadow problem
Date: 1 Dec 1998 23:34:39
Message: <3664c35f.0@news.povray.org>
thanks for the info.
here is the file, and the 2 "gifs" I'm using to map onto the card.

Thanks
 Zane


Post a reply to this message


Attachments:
Download 'shadow_prob.zip' (31 KB)

From: Margus Ramst
Subject: Re: shadow problem
Date: 2 Dec 1998 05:44:20
Message: <366519F9.CF40E499@peak.edu.ee>
Please don't send binaries (e.g. zip files & images) to this group; I have a
sloooooow connection (50 bytes per sec right now... oohhh) so I didn't manage to
DL your post.
Just post the scene file in plain text; the images aren't necessary (I really
don't think they are causing the problem)

Margus


Post a reply to this message

From: Margus Ramst
Subject: Re: shadow problem
Date: 2 Dec 1998 16:56:44
Message: <3665B63A.B2485AE4@peak.edu.ee>
OK, I managed to DL the files and solve the problem: the back part of the card
had its diffuse set to 0.
This meant the color of the surface was calculated only using the ambient value.
Sth. like finish {ambient 0.2 diffuse 0.6} might be a good value (I suggest you
also use sth. similar for the front part, the ambient seemed a bit too high
there, too)

Margus


Post a reply to this message

Copyright 2003-2023 Persistence of Vision Raytracer Pty. Ltd.