POV-Ray : Newsgroups : povray.general : Patchy stuff Server Time: 23 Sep 2017 16:32:07 GMT
  Patchy stuff (Message 1 to 5 of 5)  
From: Christopher James Huff
Subject: Patchy stuff
Date: 26 Feb 2005 21:05:23
Message: <cjameshuff-11441F.16053826022005@news.povray.org>
Here's the current state of MegaPOVPlus, my patch collection built on 
MegaPOV 1.1. The archive is a complete Unix source distribution of 
MegaPOV 1.1, with my patches applied. Unfortunately, I don't have time 
to produce as complete of a release this time, with only sketchy 
documentation and a handful of demo and testing files, but I will be 
happy to answer questions.

http://home.earthlink.net/~cjameshuff/files/megapovplus.tgz

Here are some highlights:

crackle optimizations

2D crackle

voronoi pattern (similar to crackle, but you specify the points)

enhanced function patterns (ray direction and normal are now available 
to function patterns)

lewis smooth noise generator

blob2 object (a new version of the blob object, which supports more 
components and gives smoother looking results)

updated glow patch

Various algorithm improvements, reorganization, and other stuff that may 
be useful to other patch coders.

-- 
Christopher James Huff <cja### [at] gmailcom>
POV-Ray TAG: <chr### [at] tagpovrayorg>
http://tag.povray.org/


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From: Eli
Subject: Re: Patchy stuff
Date: 1 Mar 2005 22:24:37
Message: <4224eba5$1@news.povray.org>
Taken from http://www.dotcsw.com/doc/options.html: "While the Perlin 
algorithm is widely used and efficient to generate, it suffers from 
directional artifacts and always returns 0.5 when passed whole numbers."

So that explains the rectangular artifacts we have been encountering!


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From: Christopher James Huff
Subject: Re: Patchy stuff
Date: 2 Mar 2005 00:36:22
Message: <cjameshuff-898DF0.19362101032005@news.povray.org>
In article <4224eba5$1@news.povray.org>, "Eli" <eli### [at] jehoelnet> wrote:

> Taken from http://www.dotcsw.com/doc/options.html: "While the Perlin 
> algorithm is widely used and efficient to generate, it suffers from 
> directional artifacts and always returns 0.5 when passed whole numbers."
> 
> So that explains the rectangular artifacts we have been encountering! 

Is this in response to my Lewis noise patch? It could as well be a 
separate message that got sent as a reply by accident...

There is an updated version of Perlin noise which makes the lattice 
artifacts less obvious (though it doesn't solve the problem of always 
equalling 0.5 at regular intervals), as well as giving an overall 
speedup and improvement in overall evenness of the noise. It doesn't 
entirely eliminate the problem, though. Also, the POV team has been 
aware of this for some time...probably the only reason it's not in 3.6 
is lack of time. Lewis noise is an entirely different algorithm.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: <chr### [at] tagpovrayorg>
http://tag.povray.org/


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From: gregjohn
Subject: Re: Patchy stuff
Date: 4 Mar 2005 16:40:00
Message: <web.42288e49cd38277440d56c170@news.povray.org>
Christopher James Huff <cja### [at] earthlinknet> wrote:
> Here's the current state of MegaPOVPlus, my patch collection
> built on MegaPOV 1.1. The archive is a complete Unix source
> distribution of  MegaPOV 1.1, with my patches applied.
> ...
> blob2 object (a new version of the blob object, which
> supports more  components and gives smoother looking results)
>

I'm very interested in using blobs to model people.  I've come up with all
sorts of workarounds with 3.6 SDL code to give smoother looking results.

Is it possible to show a blob{} and blob2{} attempt at a bicep & forearm?
Here, I'm simply talking of almost any combination of a single sphere and a
single cylinder where the cylinder does not go through the sphere's center.
 Could you render up a pair and post it please?

If the benefit in natural organic looking-ness were sufficiently improved, I
would buy a UNIX box and compiler just to get my hands on this patch.

Thanks.


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From: Christopher James Huff
Subject: Re: Patchy stuff
Date: 4 Mar 2005 18:38:08
Message: <cjameshuff-E61253.13380804032005@news.povray.org>
In article <web.42288e49cd38277440d56c170@news.povray.org>,
 "gregjohn" <pte### [at] yahoocom> wrote:

> Is it possible to show a blob{} and blob2{} attempt at a bicep & forearm?
> Here, I'm simply talking of almost any combination of a single sphere and a
> single cylinder where the cylinder does not go through the sphere's center.
>  Could you render up a pair and post it please?

There's nothing specifically like what you asked there, but here's a few 
examples:
http://home.earthlink.net/~cjameshuff/temp/blob2.png
http://home.earthlink.net/~cjameshuff/temp/blob2_2.png
http://home.earthlink.net/~cjameshuff/temp/tetrablob.png
http://home.earthlink.net/~cjameshuff/temp/tetrablob2.png

I'll try something like what you're asking later...I really should be  
packing to go home right now.

-- 
Christopher James Huff <cja### [at] gmailcom>
POV-Ray TAG: <chr### [at] tagpovrayorg>
http://tag.povray.org/


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From: Slime
Subject: Re: Patchy stuff
Date: 4 Mar 2005 21:13:09
Message: <4228cf65@news.povray.org>
> http://home.earthlink.net/~cjameshuff/temp/blob2.png
> http://home.earthlink.net/~cjameshuff/temp/blob2_2.png
> http://home.earthlink.net/~cjameshuff/temp/tetrablob.png
> http://home.earthlink.net/~cjameshuff/temp/tetrablob2.png


How was that implemented?

By the way, if you're looking to generate interest, sample images are a good
way to do it; show us what your patch can do.

 - Slime
 [ http://www.slimeland.com/ ]


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From: Christopher James Huff
Subject: Re: Patchy stuff
Date: 5 Mar 2005 16:01:58
Message: <cjameshuff-93F3F2.11015905032005@news.povray.org>
In article <4228cf65@news.povray.org>, "Slime" <fak### [at] emailaddress> 
wrote:

> How was that implemented?

Not entirely sure what you're asking. The basic root solver is the same 
type as the isosurface, a simple recursive bisection method. It builds a 
list of components that interact with the ray, and uses that list for 
the root solving. It just uses the first and last bounds intersection to 
limit the root finding interval, a smarter scheme will more efficiently 
bracket the individual roots.


> By the way, if you're looking to generate interest, sample images are a good
> way to do it; show us what your patch can do.

I'm working on that...I've already posted images from the most important 
patches.

-- 
Christopher James Huff <cja### [at] gmailcom>
POV-Ray TAG: <chr### [at] tagpovrayorg>
http://tag.povray.org/


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