POV-Ray : Newsgroups : povray.binaries.images : Lights instead of HDR Server Time
2 Nov 2024 14:18:48 EDT (-0400)
  Lights instead of HDR (Message 1 to 4 of 4)  
From: H  Karsten
Subject: Lights instead of HDR
Date: 28 May 2010 00:00:01
Message: <web.4bff3f1de1c9d0bddec81f370@news.povray.org>
With HDR I always have the problem that the light rays spread to much from the
picture. One of the results then is: No hard, sharp shadows...

If you would make an HDR picture with a chrome-ball from a sunny light
situation, casting sharp and hard shadows, you won't get a shadow like this in
your rendering.

So I decided to convert an HDR picture back into light sources that contains the
right color and intensity coming from the picture.

This picture contains 192 light sources as a hemisphere.

After playing with a view different HDRs, I decided to use one without a sharp
shadow - it was looking good.

Maybe some other day...

Holger :)


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From: Paolo Gibellini
Subject: Re: Lights instead of HDR
Date: 28 May 2010 05:16:33
Message: <4bff89f1$1@news.povray.org>
>H. Karsten  on date 28/05/2010 05:57 wrote:
> With HDR I always have the problem that the light rays spread to much from the
> picture. One of the results then is: No hard, sharp shadows...
>
> If you would make an HDR picture with a chrome-ball from a sunny light
> situation, casting sharp and hard shadows, you won't get a shadow like this in
> your rendering.
>
> So I decided to convert an HDR picture back into light sources that contains the
> right color and intensity coming from the picture.
>
> This picture contains 192 light sources as a hemisphere.
>
> After playing with a view different HDRs, I decided to use one without a sharp
> shadow - it was looking good.
>
> Maybe some other day...
>
> Holger :)
Nice.
Now it remembers me Starwars Empire Troops ;-)
Paolo


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From: clipka
Subject: Re: Lights instead of HDR
Date: 28 May 2010 11:35:10
Message: <4bffe2ae$1@news.povray.org>
Am 28.05.2010 05:57, schrieb H. Karsten:

> So I decided to convert an HDR picture back into light sources that contains the
> right color and intensity coming from the picture.

You may want to use the HDR picture nonetheless for reflections; in 
POV-Ray 3.7 you can achieve this by using a large sphere with the 
"no_radiosity" and "no_shadow" keywords and an ambient-only texture.


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From: Thomas de Groot
Subject: Re: Lights instead of HDR
Date: 29 May 2010 03:38:22
Message: <4c00c46e@news.povray.org>
"clipka" <ano### [at] anonymousorg> schreef in bericht 
news:4bffe2ae$1@news.povray.org...
> Am 28.05.2010 05:57, schrieb H. Karsten:
>
>> So I decided to convert an HDR picture back into light sources that 
>> contains the
>> right color and intensity coming from the picture.
>
> You may want to use the HDR picture nonetheless for reflections; in 
> POV-Ray 3.7 you can achieve this by using a large sphere with the 
> "no_radiosity" and "no_shadow" keywords and an ambient-only texture.

Ah! That is something I have to try yet!  :-)
Thanks for reminding me.

Thomas


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