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From: Zeger Knaepen
Subject: Re: Focal blur tricks
Date: 23 Feb 2008 16:06:11
Message: <47c08ac3$1@news.povray.org>
> You can even tell the difference
> without the strong highlights which makes me wonder why the default is a 
> square
> aperture.

I suppose it's faster to calculate a random location inside a square than a 
random location inside a circle.  Might not be much of a difference for 1 pixel 
and 1 sample, but it could add up to a lot for 1024x786 pixels and 10 samples 
per pixel.

cu!
-- 
#macro G(b,e)b+(e-b)*C/50#end#macro _(b,e,k,l)#local C=0;#while(C<50)
sphere{G(b,e)+3*z.1pigment{rgb G(k,l)}finish{ambient 1}}#local C=C+1;
#end#end _(y-x,y,x,x+y)_(y,-x-y,x+y,y)_(-x-y,-y,y,y+z)_(-y,y,y+z,x+y)
_(0x+y.5+y/2x)_(0x-y.5+y/2x)            // ZK http://www.povplace.com


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From: C  Cappai
Subject: Re: Focal blur tricks
Date: 23 Feb 2008 16:40:00
Message: <web.47c091a2806ad5e46a3b8b10@news.povray.org>
"triple_r" <rre### [at] hotmailcom> wrote:
> "triple_r" <rre### [at] hotmailcom> wrote:
> > I think it would require a direct patch into
> > POV-Ray to fix the problem.
>
> So with very little effort, here's the result of my patched POV.  It's hardly
> fair to call it that since it's only a couple lines and there's no SDL
> interface for it.  It just reads a grayscale ppm file and varies the density of
> the sample grid according to the image.  You can even tell the difference
> without the strong highlights which makes me wonder why the default is a square
> aperture.  Not quite sure when that would be preferable, but maybe people don't
> use strong focal blur too often.
>
>  - Ricky

Wow!

I want so much that all this was implemented in the next beta of POV-Ray!


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From: nemesis
Subject: Re: Focal blur tricks
Date: 23 Feb 2008 16:40:49
Message: <47c092e1$1@news.povray.org>
man, that's so amazing I don't even know how to thank you!  Send it to 
the povteam right now!

I don't know if a povsymbol aperture is that realistic, but as artistic 
license it's wonderful. :)  and the hexagon and circular one are spot-on!

let's workout a syntax extension for it:

camera {
	aperture .02 blur_samples 60 shape circular | hexagon | image
}

how's it?


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From: Nicolas Alvarez
Subject: Re: Focal blur tricks
Date: 23 Feb 2008 17:50:09
Message: <47c0a321@news.povray.org>

> "triple_r" <rre### [at] hotmailcom> wrote:
>> I think it would require a direct patch into
>> POV-Ray to fix the problem.
> 
> So with very little effort, here's the result of my patched POV.  It's hardly
> fair to call it that since it's only a couple lines and there's no SDL
> interface for it.  It just reads a grayscale ppm file and varies the density of
> the sample grid according to the image.  You can even tell the difference
> without the strong highlights which makes me wonder why the default is a square
> aperture.  Not quite sure when that would be preferable, but maybe people don't
> use strong focal blur too often.
> 

Did you base your patch on 3.6 or 3.7 code?


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From: triple r
Subject: Re: Focal blur tricks
Date: 23 Feb 2008 18:25:01
Message: <web.47c0ab23806ad5e4ae42298f0@news.povray.org>
"Zeger Knaepen" <zeg### [at] povplacecom> wrote:
> > You can even tell the difference
> > without the strong highlights which makes me wonder why the default is a
> > square
> > aperture.
>
> I suppose it's faster to calculate a random location inside a square than a
> random location inside a circle.  Might not be much of a difference for 1 pixel
> and 1 sample, but it could add up to a lot for 1024x786 pixels and 10 samples
> per pixel.

Well that's the interesting part.  It seems to use something like a grid with
jitter, but it's all precalculated before the render.  So it doesn't matter
what shape you choose - as best as I can tell, it's just a list of points when
rendering.

 - Ricky


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From: triple r
Subject: Re: Focal blur tricks
Date: 23 Feb 2008 18:30:00
Message: <web.47c0ab9f806ad5e4ae42298f0@news.povray.org>
"C. Cappai" <nomail@nomail> wrote:

> Wow!
>
> I want so much that all this was implemented in the next beta of POV-Ray!

It's nothing POV-Ray can't do already, it's just square and ugly by default.
Trivial to change.

 - Ricky


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From: Zeger Knaepen
Subject: Re: Focal blur tricks
Date: 24 Feb 2008 06:54:16
Message: <47c15ae8$1@news.povray.org>
"nemesis" <nam### [at] nospamgmailcom> wrote in message 
news:47c092e1$1@news.povray.org...
> man, that's so amazing I don't even know how to thank you!  Send it to the 
> povteam right now!
>
> I don't know if a povsymbol aperture is that realistic, but as artistic 
> license it's wonderful. :)  and the hexagon and circular one are spot-on!
>
> let's workout a syntax extension for it:
>
> camera {
> aperture .02 blur_samples 60 shape circular | hexagon | image
> }
>
> how's it?

there's a bokeh-patch for povray that accepts any pigment as shape.  I think 
that's actually the best way to do it. (it's the bokeh_pigment_patch that's 
referenced on the MegaPOV-website, but that's the only hit on google, so I 
suppose it's not available anymore)

cu!
-- 
#macro G(b,e)b+(e-b)*C/50#end#macro _(b,e,k,l)#local C=0;#while(C<50)
sphere{G(b,e)+3*z.1pigment{rgb G(k,l)}finish{ambient 1}}#local C=C+1;
#end#end _(y-x,y,x,x+y)_(y,-x-y,x+y,y)_(-x-y,-y,y,y+z)_(-y,y,y+z,x+y)
_(0x+y.5+y/2x)_(0x-y.5+y/2x)            // ZK http://www.povplace.com


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From: Nekar
Subject: Re: Focal blur tricks
Date: 24 Feb 2008 07:46:47
Message: <47c16737@news.povray.org>
Ooh, lovely! Will it do the same with light sources? I'm thinking of a
street scene at night.


--
- Nekar X -


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From: William Tracy
Subject: Re: Focal blur tricks
Date: 24 Feb 2008 12:49:43
Message: <47c1ae37$1@news.povray.org>
Nekar wrote:
> Ooh, lovely! Will it do the same with light sources? I'm thinking of a
> street scene at night.

Probably not, but it probably would work if the lights had a really 
bright looks_like object.

-- 
William Tracy
afi### [at] gmailcom -- wtr### [at] calpolyedu

    It occurred to him that now he was going to be not only the first 
man on Mars, but the first detective. He grinned at the thought, and the 
last action of the omegendorph set his nerves aglow.
     -- Kim Stanley Robinson, _Red Mars_


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From: Gilles Tran
Subject: Re: Focal blur tricks
Date: 24 Feb 2008 14:49:32
Message: <47c1ca4c$1@news.povray.org>

web.47bfa2bb806ad5e4ae42298f0@news.povray.org...
> You'll notice in these images that the bokeh are just below a comfortable 
> noise
> threshold, but the rest of the scene is extremely oversampled.  That fix 
> might
> not be so easy, but if it could be accomplished, would make the focal_blur 
> much
> more powerful.
>
> - Ricky

Here's a link to Mael's POV-Ray patch with the bokeh feature (and other cool 
stuff)
http://pov.monde.free.fr/mael/mlpov081.html

G.

-- 
**********************
http://www.oyonale.com
**********************
- Graphic experiments
- POV-Ray, Cinema 4D and Poser computer art
- Posters


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