Steven Pigeon wrote:
> 
> > Remco de Korte wrote:
> > >


> > > I would like to build it from small parts like triangles and I
> know

> thinking
> > > about a number of points randomly scattered over the surface and
> then
> > > make triangles with those.
> 
> There are numerous ways to do "spheres" with lots of polygons.The best
> I can
> see is to use a "Buckminster-Fuller"-type polyedron.
> You start with an icosaedron (20 faces... you know, d&d 20 sided
> dice) then progressively divide the faces into 4 other triangles. You
> keep dividing triangles until you've got a satisfying result.
> 
> IMHO, there's no real use to that. A sphere is much better repre-
> sented when it's a z^2+y^2+X^2=r^2 form; especially if your
> only goal is to render a simple sphere.
> 
> On the other hand, the buckminsterized sphere provide almost
> uniform sampling points on the sphere; you dont have the point
> concentration effect you have with polar/spheric coordinates. It
> is also ideal for spheric fractals (or "rocks", either John's
> generator,
> http://www.erols.com/vansickl/rock.htm, or my own generator,
> http://www.iro.umontreal.ca/~pigeon/pub/PovPage/RockGen/RockGen.html
> (with source included)).
> 
> I first buckminsterized spheres to do uniform sampling, in the
> context of environment mapping (to reduce rendering time).
> Then for to fractal planets.
> 
> Best,
> 
>     S.
>  ----------------------------------------------------------
> Steven Pigeon                     Ph. D. Student.
> University of Montreal.
> pig### [at] iroumontrealca           Topics: data compression,
> pig### [at] jspumontrealca          signal processing,
> ste### [at] researchattcom           non stationnary signals
>                                   and wavelets.
> ----------------------------------------------------------
>          http://www.iro.umontreal.ca/~pigeon

I downloaded the program Ken mentioned (Geodome1). There's a really nice
image by the same name at the FTP-site.
I had a look at the program and though it does do what it's supposed to
do it wasn't exactly what I needed (my question was a bit vague). I had
a look at the source though and that brought me to the idea to do
something like you describe here: a recursive function, creating a
sphere with triangles, subdivided by triangles, etc. With this I could
do what I actually intended to: to blow up a sphere into fragments.

You're right that it wouldn't be very smart to use this method if you'd
just need a sphere. Even with smooth-triangles I found that there were
seams all over the object. But if you'd need any 'special effects' (
abump in a sphere) you could consider this (or use a blob).

Regards,

Remco de Korte
http://www.xs4all.nl/~remcodek

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> do what I actually intended to: to blow up a sphere into fragments.

For this application, also consider :

http://www.geocities.com/SiliconValley/Lakes/1434/explode.html

a generalized explosion macro by the incredible Chris Colfax
(who accomplishes with include files things for which normal folk
must hack the source....)

Dan

-- 
http://www.flash.net/~djconnel/

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Dan Connelly wrote:

> For this application, also consider :
> http://www.geocities.com/SiliconValley/Lakes/1434/explode.html
> a generalized explosion macro by the incredible Chris Colfax
> (who accomplishes with include files things for which normal folk
> must hack the source....)
>
> Dan

Can people who sit around designing computer graphic images
using POV-Ray be concidered normal folk ?

Ken

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Ken wrote:

> > (who accomplishes with include files things for which normal folk
> > must hack the source....)
> >
> > Dan
>
> Can people who sit around designing computer graphic images
> using POV-Ray be concidered normal folk ?
>
> Ken

No, of course not :-) Especially those who have their own
builds and home-made companion programs ...!


Best,

    S.


----------------------------------------------------------
Steven Pigeon                     Ph. D. Student.
University of Montreal.
pig### [at] iroumontrealca           Topics: data compression,
pig### [at] jspumontrealca          signal processing,
ste### [at] researchattcom           non stationnary signals
                                  and wavelets.
----------------------------------------------------------
         http://www.iro.umontreal.ca/~pigeon

Post a reply to this message

Ken wrote in message <35FBC490.FCEDA158@pacbell.net>...
>Can people who sit around designing computer graphic images

>using POV-Ray be concidered normal folk ?

>

>Ken

>


I hear this question, but more specifically asked than here, about a dozen times every
day. My mother, my father, my brother, all my friends, my girlfriend... Now I hear it
from a fellow POVer. They can't be all wrong, you know. I guess I'll have to admit I'm
"kinda nuts".

Peter

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Same here ;-)

Sad isn't it? ;-)

I'm sitting here (and have been for the last 4 hours) stairing at my
computer, 3DSMAX and Riven boxes, my real-life "Elwood" figurine, several
CD-R and CD-RWs, two massive Escher prints, my scanner and printer, a
decoded Playstation Lara Croft animation from TR-II, an 8-inch high set of
3DSMAX tutorials and manuals (oh the upgrade tromurs!) and a stack of CDs
numbering about 50. (listening to Chroma Key, http://www.chromakey.com)

WHAT AM I DOING WITH MYSELF WHEN THE BEACH, SUN, SAND AND OCEAN IS JUST A 50
METRE WALK AWAY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

And yet, strangely, I fell comforted by my room [SLAP!!!!!!!!] "GET A
GRIP!!!" :-)

--
Lance.

P.S.  I haven't been able to receive any emails for the last 4-5 days (and I
still can't), so if you've mailed me and I didn't reply, that's why!

---
For the latest MAX plug-ins, images and much more, go to:
The Zone - http://come.to/the.zone

Post a reply to this message

Lance Birch wrote:
> 
> Same here ;-)
> 
> Sad isn't it? ;-)
> 
> I'm sitting here (and have been for the last 4 hours) stairing at my
> computer, 3DSMAX and Riven boxes, my real-life "Elwood" figurine,
> several
> CD-R and CD-RWs, two massive Escher prints, my scanner and printer, a
> decoded Playstation Lara Croft animation from TR-II, an 8-inch high
> set of
> 3DSMAX tutorials and manuals (oh the upgrade tromurs!) and a stack of
> CDs
> numbering about 50. (listening to Chroma Key, http://www.chromakey.com
> )
> 
> WHAT AM I DOING WITH MYSELF WHEN THE BEACH, SUN, SAND AND OCEAN IS
> JUST A 50
> METRE WALK
> AWAY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
> 
> And yet, strangely, I fell comforted by my room [SLAP!!!!!!!!] "GET A
> GRIP!!!" :-)
> 
> --
> Lance.
> 

Oh, man, I could do with some sunny beach!
I was just of on a holiday which basically came down to a weeks worth of
rain and I must admit I was glad I could return to my digital addiction.

But if you could render me some sunshine I'd be most pleased ;-)

Remco

Post a reply to this message

Remco de Korte wrote in message <35FFAE5D.8F6992F4@xs4all.nl>...
>
>Oh, man, I could do with some sunny beach!
>I was just of on a holiday which basically came down to a weeks worth of
>rain and I must admit I was glad I could return to my digital addiction.
>
>But if you could render me some sunshine I'd be most pleased ;-)
>
>Remco
>


I went to the seaside this summer with an experiment in my head. I went
there with a group of computer illiterates (i.e. normal ordinary sane
people), I had my guitar and I wanted to see how long could I stand without
my computer. Well, I had to take this for ten horrible sunny days and when I
came back I had filled about fifty pages of POV code in a notebook, I had
grown two more centimeters of beard, and my hands were trembling <G>. The
guys were bored to death with Bill Gates jokes and "you know you've been
raytracing too long if..." stuff and couldn't dig why this nutter had
collected about 500 seashells just to try to write a generalized .inc (I
gave up on that), whatever that is. They all agreed he needed a nice white
room in a quiet place with a lot of trees and nice calm doctors all around
the place. I guess this says it all...

Peter

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I don't look out the window at the sky anymore because it no longer
looks realistic and "they" won't allow me to change it. Sigh !

Ken


Peter Popov wrote:

> I went to the seaside this summer with an experiment in my head. I went
> there with a group of computer illiterates (i.e. normal ordinary sane
> people), I had my guitar and I wanted to see how long could I stand without
> my computer. Well, I had to take this for ten horrible sunny days and when I
> came back I had filled about fifty pages of POV code in a notebook, I had
> grown two more centimeters of beard, and my hands were trembling <G>. The
> guys were bored to death with Bill Gates jokes and "you know you've been
> raytracing too long if..." stuff and couldn't dig why this nutter had
> collected about 500 seashells just to try to write a generalized .inc (I
> gave up on that), whatever that is. They all agreed he needed a nice white
> room in a quiet place with a lot of trees and nice calm doctors all around
> the place. I guess this says it all...
>
> Peter

Post a reply to this message

Ken wrote:
> 
> I don't look out the window at the sky anymore because it no longer
> looks realistic and "they" won't allow me to change it. Sigh !

From "Fractals, Chaos, Power Laws" by Manfred Schroeder (1990):

"Color Plate 5 shows a photograph, taken by the author, of a natural
cloud that rivals the realism of computer-generated nebulosities."

Jerry Anning
cle### [at] dholcom

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