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1 Aug 2024 06:25:27 EDT (-0400)
  Learning about Proximity patterns (Message 1 to 7 of 7)  
From: Kirk Andrews
Subject: Learning about Proximity patterns
Date: 7 Dec 2008 13:05:01
Message: <web.493c1033b62e41ea198b63d90@news.povray.org>
Thanks to Sam for introducing me to the concept.  I had wanted to do something
like that before, but had never thought of using averaging an object pattern.
Some initial results:


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From: stbenge
Subject: Re: Learning about Proximity patterns
Date: 7 Dec 2008 17:59:44
Message: <493c5560@news.povray.org>
Kirk Andrews wrote:
> Thanks to Sam for introducing me to the concept.  I had wanted to do something
> like that before, but had never thought of using averaging an object pattern.
> Some initial results:

Kirk,

That looks nice! It definitely has an aged appearance :) Is the object 
CSG? I'm guessing it is, since you averaged object patterns together to 
get the proximity effect. This would look even better in a complete scene ;)

I have an array of 251 points set in a regular spherical/cubic fashion 
that I use for this very purpose. It effectively distributes the object 
pattern in 3D space, thus reducing any inefficiencies arising from 
complete randomization. A little randomization, though, helps avoid 
other artifacts associated with such a regular pattern. Attached is a 
pic showing how the elements are placed.

Sam


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From: Bill Pragnell
Subject: Re: Learning about Proximity patterns
Date: 7 Dec 2008 18:20:00
Message: <web.493c59b791f0b832ea3236f00@news.povray.org>
> Kirk Andrews wrote:
> > Thanks to Sam for introducing me to the concept.  I had wanted to do something
> > like that before, but had never thought of using averaging an object pattern.
> > Some initial results:

Ooh yes, this is a lovely technique. Thanks for the hint guys, I would never
have thought of using object patterns in this way. I must play with this in
future projects. Attached is my best experiment of the day, nowhere near as
believable as that column but it's just proof-of-concept for me!

stbenge <THI### [at] hotmailcom> wrote:
> I have an array of 251 points set in a regular spherical/cubic fashion
> that I use for this very purpose. It effectively distributes the object
> pattern in 3D space, thus reducing any inefficiencies arising from
> complete randomization. A little randomization, though, helps avoid
> other artifacts associated with such a regular pattern. Attached is a
> pic showing how the elements are placed.

I'm using a pure random distribution. I guess you could just jitter your points
in that illustration to keep a random element if it was ending up too regular.

This is interesting stuff. :)

Bill


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From: William Tracy
Subject: Re: Learning about Proximity patterns
Date: 8 Dec 2008 18:10:40
Message: <493da970$1@news.povray.org>
/me wonders if this could be combined with a greeble macro. :-D

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

I disapprove of what you say, but I will defend to the death your right 
to say it.
     -- Evelyn Beatrice Hall, frequently mis-attributed to Voltaire


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From: Jim Charter
Subject: Re: Learning about Proximity patterns
Date: 8 Dec 2008 19:01:49
Message: <493db56d@news.povray.org>
Bill Pragnell wrote:
>>Kirk Andrews wrote:
>>
>>>Thanks to Sam for introducing me to the concept.  I had wanted to do something
>>>like that before, but had never thought of using averaging an object pattern.
>>>Some initial results:
> 
> 
> Ooh yes, this is a lovely technique. Thanks for the hint guys, I would never
> have thought of using object patterns in this way. I must play with this in
> future projects. Attached is my best experiment of the day, nowhere near as
> believable as that column but it's just proof-of-concept for me!
> 
> stbenge <THI### [at] hotmailcom> wrote:
> 
>>I have an array of 251 points set in a regular spherical/cubic fashion
>>that I use for this very purpose. It effectively distributes the object
>>pattern in 3D space, thus reducing any inefficiencies arising from
>>complete randomization. A little randomization, though, helps avoid
>>other artifacts associated with such a regular pattern. Attached is a
>>pic showing how the elements are placed.
> 
> 
> I'm using a pure random distribution. I guess you could just jitter your points
> in that illustration to keep a random element if it was ending up too regular.
> 
> This is interesting stuff. :)
> 
> Bill
> 
> 
> ------------------------------------------------------------------------
> 
Though I already replied so second reply:
Yes Bill, with your mesh macros you can do the same averaging in certain 
cases before applying the pattern to the mesh to get some similar 
weathering effects.  Here I jitterd and averaged the radial pattern that 
was used to get the fluting in the column to get a weathered look, then 
applied it to the mesh.

http://tinyurl.com/5oqr7u


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From: Bill Pragnell
Subject: Re: Learning about Proximity patterns
Date: 9 Dec 2008 04:10:00
Message: <web.493e356091f0b832d5b77e4a0@news.povray.org>
Jim Charter <jrc### [at] msncom> wrote:
> Though I already replied so second reply:
> Yes Bill, with your mesh macros you can do the same averaging in certain
> cases before applying the pattern to the mesh to get some similar
> weathering effects.  Here I jitterd and averaged the radial pattern that
> was used to get the fluting in the column to get a weathered look, then
> applied it to the mesh.

Yes, of course. I remember thinking this looked good but I couldn't immediately
see why (compared with my experiments). Once I know what to look for, I can see
it. I hadn't thought of jittering the source pattern either, my quick test above
is derived from just the base shape, which is why it doesn't quite look right.

For even greater realism, I must also experiment with Sam's fastprox macro,
since it appears to only require a simple patch to make it work with meshes.

*rubs hands with enthusiasm*


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From: Thomas de Groot
Subject: Re: Learning about Proximity patterns
Date: 9 Dec 2008 08:14:20
Message: <493e6f2c@news.povray.org>
"Bill Pragnell" <bil### [at] hotmailcom> schreef in bericht 
news:web.493e356091f0b832d5b77e4a0@news.povray.org...
>
> For even greater realism, I must also experiment with Sam's fastprox 
> macro,
> since it appears to only require a simple patch to make it work with 
> meshes.
>
> *rubs hands with enthusiasm*
>
>

It does. This is a rapid test of Sam's macros using a mesh2.

From left to right:
  fastProx()
  fastProx2()
  fastProx3()
  fastSSS2()


Thomas


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