POV-Ray : Newsgroups : povray.general : focal blur at great distances Server Time
17 Nov 2024 13:20:37 EST (-0500)
  focal blur at great distances (Message 1 to 8 of 8)  
From: Greg M  Johnson
Subject: focal blur at great distances
Date: 3 Mar 2003 10:50:18
Message: <3e6379ba@news.povray.org>
I wanted to simulate a telescope:  First have the focal point go from near
the camera to an object far away (<<10 units tall but >100 units away).

I found that the aperture settings only gave me two results:

1) Nothing is really blurry at all.
2) Everything is really blurry, including an object placed at  the
focal_point .


I desired to have a faraway object be in focus but objects twice the
distance (focal_point - camera_location)  to be blurry.


It almost seems like we're missing a parameter, or that the effect of the
aperture is messed up by the scale of the scene you're in.


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From: Peter Hertel
Subject: Re: focal blur at great distances
Date: 3 Mar 2003 12:06:25
Message: <3e638b91$1@news.povray.org>
*snip*

I use DoF.inc (Depth Of Field) when I set up focal blur. I haven't tried
the thing you describe, but perhaps looking at the file will give you
some answers?
http://www.wozzeck.net/images/DoF.html

--
Peter


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From: Greg M  Johnson
Subject: Re: focal blur at great distances
Date: 3 Mar 2003 16:37:44
Message: <3e63cb28$1@news.povray.org>
Faskinating.  Povray should work like this.


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From: Alan Kong
Subject: Re: focal blur at great distances
Date: 4 Mar 2003 06:27:59
Message: <ca396vop8dlvgmt58f0f17kihssfdfhqnm@4ax.com>
On Mon, 3 Mar 2003 10:49:47 -0500 "Greg M. Johnson"
<gregj:-)565### [at] aolcom> wrote:

>It almost seems like we're missing a parameter, or that the effect of the
>aperture is messed up by the scale of the scene you're in.

  How about a simple test scene (with lighting, focal blur settings)
using simple objects, so we can see what sort of scale you're talking
about?

-- 
Alan
ako### [at] povrayorg
a k o n g <at> p o v r a y <dot> o r g


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From: Greg M  Johnson
Subject: Re: focal blur at great distances
Date: 4 Mar 2003 08:33:40
Message: <3e64ab34$1@news.povray.org>
Doh?

When I gutted the scene and replaced a blob character with a sphere,  I got
the response I'd expected. Perhaps my blob's center ain't at <0,0,0>.

In any case, I'm glad to have flushed out (I mean like duck-hunting, not
like the lavatory-using)  Peter's  DoF.inc file



"Alan Kong" <ako### [at] povrayWWWSPAMCOMorg> wrote in message
news:ca396vop8dlvgmt58f0f17kihssfdfhqnm@4ax.com...
>
>   How about a simple test scene (with lighting, focal blur settings)
> using simple objects, so we can see what sort of scale you're talking
> about?
>


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From: Tom Melly
Subject: Re: focal blur at great distances
Date: 4 Mar 2003 08:39:56
Message: <3e64acac$1@news.povray.org>
"Greg M. Johnson" <gregj:-)565### [at] aolcom> wrote in message
news:3e64ab34$1@news.povray.org...
> Doh?
>
> When I gutted the scene and replaced a blob character with a sphere,  I got
> the response I'd expected. Perhaps my blob's center ain't at <0,0,0>.

Sounds odd. Can you post a minimal scene that allows switching between a blob
and a sphere?


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From: Greg M  Johnson
Subject: Re: focal blur at great distances
Date: 4 Mar 2003 09:42:28
Message: <3e64bb54$1@news.povray.org>
Someday I'll release lots of my blob characters (as if people were dying to
get their hands on them, I know).  But what I really meant is that I had :

i)  a focal_point set up at a variable called LOOK_AT, and

ii) an object{diff2 translate LOOK_AT}  , where diff2 was a union of a
50-component blob and some eyeballs spheres, with who knows how many
translate statements.

I'm not making a general statement about blobs where say  sphere{0,2,1} does
end up not centered at <0,0,0>, which I believe is the reason for your
curiosity.  I'm saying that my diff2 code is so messy that perhaps its
center wasn't near <0,0,0>.


"Tom Melly" <tom### [at] tomandlucouk> wrote in message
news:3e64acac$1@news.povray.org...
>
> Sounds odd. Can you post a minimal scene that allows switching between a
blob
> and a sphere?
>
>


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From: Tom Melly
Subject: Re: focal blur at great distances
Date: 4 Mar 2003 10:41:25
Message: <3e64c925@news.povray.org>
"Greg M. Johnson" <gregj:-)565### [at] aolcom> wrote in message
news:3e64bb54$1@news.povray.org...
> Someday I'll release lots of my blob characters (as if people were dying to

<snip>

Ah - I know the feeling. I once lost some very complex CSG like that. Turned out
it ended up in restricted air-space, and the Arcturians have refused to give it
back.


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