POV-Ray : Newsgroups : povray.binaries.images : Zeger's Greebles revisited (attn. Thomas De Groot) Server Time
6 Aug 2024 16:58:02 EDT (-0400)
  Zeger's Greebles revisited (attn. Thomas De Groot) (Message 1 to 7 of 7)  
From: Doctor John
Subject: Zeger's Greebles revisited (attn. Thomas De Groot)
Date: 16 Oct 2006 05:56:34
Message: <45335752@news.povray.org>
Mainly for Thomas but all are welcome to join in.

I couldn't find my original changes to greebles.inc so I started working on 
a fresh version last night. The only thing that I've changed is line 31 (see 
attached) and now greebletest.pov renders but we still appear to have some 
problems (ignoring the multiple error messages which I will fix shortly) in 
that the left side of the cylindrical object seems to be dissolving away - 
any ideas what might be causing this?

Secondly, any chance of you translating the comments into English so that I 
have a fighting chance of understanding Zeger's thinking while he wrote the 
original code.

John

-- 
"Please refrain from fondling the nymphs and sprites
- it makes them giggly and skittish.
Thank you for your co-operation.
The Management"


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Attachments:
Download 'greebletest.jpg' (36 KB) Download 'greebles-inc_truncated.txt' (2 KB)

Preview of image 'greebletest.jpg'
greebletest.jpg

From: Thomas de Groot
Subject: Re: Zeger's Greebles revisited (attn. Thomas De Groot)
Date: 16 Oct 2006 10:43:01
Message: <45339a75$1@news.povray.org>
That looks very good!
I can translate the comments and post them back of course (except is Zeger 
is more rapid ;-) )

Thanks a lot for the good work!

Thomas


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From: Doctor John
Subject: Re: Zeger's Greebles revisited (attn. Thomas De Groot)
Date: 16 Oct 2006 10:54:06
Message: <45339d0e@news.povray.org>
"Thomas de Groot" <t.d### [at] internlnet> wrote in message 
news:45339a75$1@news.povray.org...
> That looks very good!
> I can translate the comments and post them back of course (except is Zeger 
> is more rapid ;-) )
>
> Thanks a lot for the good work!
>
> Thomas
More to come as I get my head around exactly how the various macros interact 
with each other. The change I made is just a quick fix; I'm sure there's a 
better way of doing it (possibly using Diepte which as far as I can see 
limits the recursion depth)

John

-- 
"Please refrain from fondling the nymphs and sprites
- it makes them giggly and skittish.
Thank you for your co-operation.
The Management"


Post a reply to this message

From: Zeger Knaepen
Subject: Re: Zeger's Greebles revisited (attn. Thomas De Groot)
Date: 16 Oct 2006 13:16:39
Message: <4533be77$1@news.povray.org>
"Thomas de Groot" <t.d### [at] internlnet> wrote in message
news:45339a75$1@news.povray.org...
> That looks very good!
> I can translate the comments and post them back of course (except is Zeger
> is more rapid ;-) )

I very much doubt I will be, very little time at the moment :(

sorry !

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: Zeger Knaepen
Subject: Re: Zeger's Greebles revisited (attn. Thomas De Groot)
Date: 16 Oct 2006 13:29:50
Message: <4533c18e$1@news.povray.org>
"Doctor John" <doc### [at] linuxmailorg> wrote in message
news:45339d0e@news.povray.org...
> "Thomas de Groot" <t.d### [at] internlnet> wrote in message
> news:45339a75$1@news.povray.org...
> > That looks very good!
> > I can translate the comments and post them back of course (except is Zeger
> > is more rapid ;-) )
> >
> > Thanks a lot for the good work!
> >
> > Thomas
> More to come as I get my head around exactly how the various macros interact
> with each other. The change I made is just a quick fix; I'm sure there's a
> better way of doing it (possibly using Diepte which as far as I can see
> limits the recursion depth)

as far as I can remember, that's right.

Actually, I believe I *did* kind of fix it, you know!  The problem was that the
points on the polygons (the greeble-cells actually) were too close together,
which caused the official POV-Ray to stop with an error.  However, if I scale
the location of the points by, let's say 10000, and then scale the polygon by
1/10000, then it worked okay... not a perfect fix of course, and won't work in
every case, but the only other way is to check every point of the polygon with
every next point, in a *new* loop before the loop where the polygon is created.
Might slow things down, cause you'd have to do that for every greeble-cell
(which can be quite a few, depending on the value Diepte).

the code to change for the "fix" is, I believe, in the macro RoundPrism(), right
at the end:
change:

  #if (Aantal2>2)
  polygon {
   Aantal2,
   #local Tel=0;
   #while (Tel<Aantal)
    #ifdef(Points2[Tel])<Points2[Tel].x,Points2[Tel].y>
    #end
    #local Tel=Tel+1;
   #end
   translate -z*H
  }
  #end

into:

  #if (Aantal2>2)
  polygon {
   Aantal2,
   #local Tel=0;
   #while (Tel<Aantal)
    #ifdef(Points2[Tel])<Points2[Tel].x,Points2[Tel].y>*100000
    #end
    #local Tel=Tel+1;
   #end
   scale 1/100000
   translate -z*H
  }
  #end


and it should work.

Hope that helps :)

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: Thomas de Groot
Subject: Re: Zeger's Greebles revisited (attn. Thomas De Groot): translation posted
Date: 17 Oct 2006 03:49:41
Message: <45348b15@news.povray.org>
I have posted a revised version of Zeger's greebles.inc in p.b.s-f
I corrected the code following Zeger's post above, and translated the 
comment lines. If any further doubts, just yell.

Thomas


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From: Doctor John
Subject: Re: Zeger's Greebles revisited (attn. Thomas De Groot): translation posted
Date: 17 Oct 2006 10:04:09
Message: <4534e2d9$1@news.povray.org>
"Thomas de Groot" <t.d### [at] internlnet> wrote in message 
news:45348b15@news.povray.org...
>I have posted a revised version of Zeger's greebles.inc in p.b.s-f
> I corrected the code following Zeger's post above, and translated the 
> comment lines. If any further doubts, just yell.
>
> Thomas
Thanks for the work. Hopefully it should be plain sailing from here on in

John

-- 
"Please refrain from fondling the nymphs and sprites
- it makes them giggly and skittish.
Thank you for your co-operation.
The Management"


Post a reply to this message

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