POV-Ray : Newsgroups : povray.general : I know this can not be a first Server Time
9 Aug 2024 01:24:58 EDT (-0400)
  I know this can not be a first (Message 1 to 8 of 8)  
From: Matt Giwer
Subject: I know this can not be a first
Date: 27 Sep 2000 20:36:06
Message: <39D29280.FAEFC4B2@ij.net>
For some time I have been considering how to make extremely complex
shapes such as Babylon 5. I considered on huge mesh but that is hugely
memory intensive and has smoothing problems. Then a spline fit to points
and making as surface of rotation but that precludes sharp angles that
will hold up when moving to a close view. 

	Both suffer from the problem of producing a texture that will survive a
closeup view. 

	Finally it dawns on me to try to make a model that imitates life.
Consider it the Lego approach rather than brick texture approach. I have
not tried this yet. I am presenting it as a way of talking it outself to
myself and inviting comments. 

	A structure such as B5 would be a set of plates welded to a framework.
Thus for each area of the structure, regardless of how odd the shape,
only need only one mesh (or heighfield or CGS) rotated and translated
enough times to make a ring. Another plate can be a junction to a
different shape. Each plate can have a texture that survives a closeup
and would hopefully appear realistic with a long shot. At least it will
look consistant. 

	Creating each plate by means other than CGS will be a modest to severe
math challenge depending upon the shape desired. And CGS would not
always be applicable unless spline section of rotation. And the more
methods are mixed the more difficult making the math used for each
congruent. 

	Obviously there are downsides to this method. It appears essential to
do everything from start to finish not only with a calculator but with
everything in terms of analytic geometry, I think called algebraic
geometry since I went through the drill. If CGS then the size of the
surface is defined in terms of angular size and the cutting planes
positioned by those angles. 

-- 
Alice: I'm voting for Gore because he is handsome.
Sarah: I'm voting fore Bush because he is cute.
Remember guys, those girls are voting. 
	-- The Iron Webmaster, 34


Post a reply to this message

From: John VanSickle
Subject: Re: I know this can not be a first
Date: 27 Sep 2000 23:05:32
Message: <39D2B670.E3822B48@erols.com>
Matt Giwer wrote:
> 
> For some time I have been considering how to make extremely complex
> shapes such as Babylon 5. I considered on huge mesh but that is hugely
> memory intensive and has smoothing problems.

Smooth triangles take up something like 144 bytes each when they are
part of a mesh.

The Greb (one of my regular IRTC models) is made of ten different
meshes, some used once, some used twice, and a couple used four times.
Together there are over thirty thousand triangles in the Greb, but due
to mesh copying only 13,376 need be kept.  Together the meshes take up
around 2 Megs of ram, and if I add Greb, it takes only a little bit
mopre RAM.

Regards,
John


Post a reply to this message

From: Matt Giwer
Subject: Re: I know this can not be a first
Date: 28 Sep 2000 06:05:39
Message: <39D317F3.2D05F51B@ij.net>
John VanSickle wrote:
> 
> Matt Giwer wrote:
> >
> > For some time I have been considering how to make extremely complex
> > shapes such as Babylon 5. I considered on huge mesh but that is hugely
> > memory intensive and has smoothing problems.
> 
> Smooth triangles take up something like 144 bytes each when they are
> part of a mesh.
> 
> The Greb (one of my regular IRTC models) is made of ten different
> meshes, some used once, some used twice, and a couple used four times.
> Together there are over thirty thousand triangles in the Greb, but due
> to mesh copying only 13,376 need be kept.  Together the meshes take up
> around 2 Megs of ram, and if I add Greb, it takes only a little bit
> mopre RAM.

	Yes, but ... 

	On binaries I have posted several examples of what I am talking about
with the images and migrating from meshes to heighfields for problems of
computational loading with an acceptable 333/128 PII linux machine. I
produced 13 MB mesh file to render. The console had no problem but KDE
graphics window did. I do not explain that, I only observe it. 

	That said, I don't know what the hell is going on. I documented it all
and with source code and that is what happens. 

	I was running about 256x256x2 triangles and X11/KDE on linux was
unhappy but a console terminal ran it quite well than thank you. It is
really something I have to document and put before both the X11 and KDE
folks and let them fight it out, not me. Linux (Redhat) per se is
totally stable without their add-ons. 

-- 
In the 19th century the British decided they were
naturally fit to rule the world. So much for the
rulers of the world. 
	-- The Iron Webmaster, 143


Post a reply to this message

From: Tor Olav Kristensen
Subject: Re: I know this can not be a first
Date: 28 Sep 2000 09:26:46
Message: <39D346E0.1EBCB64@hotmail.com>
Matt Giwer wrote:

>   ...
>         Creating each plate by means other than CGS will be a modest to severe
> math challenge depending upon the shape desired. And CGS would not
> always be applicable unless spline section of rotation. And the more
> methods are mixed the more difficult making the math used for each
> congruent.
>
>         Obviously there are downsides to this method. It appears essential to
> do everything from start to finish not only with a calculator but with
> everything in terms of analytic geometry, I think called algebraic
> geometry since I went through the drill. If CGS then the size of the
> surface is defined in terms of angular size and the cutting planes
> positioned by those angles.
> ...

I find your thoughts interesting.

Earlier I have worked on some macros that make smooth transitions
between some of the shapes formed by CSG primitives in POV-Ray.
(But since there did not seem to be much interest for such macros I
did not develop these much further.)

You may have a look at the posts in this thread to see if this is of any
relevance to your thoughts/plans:

news://news.povray.org/38F90794.CA6221FD%40hotmail.com
(My thread started 16. April 2000 "Playing with CSG" to
povray.binaries.images.)


Tor Olav
--
mailto:tor### [at] hotmailcom
http://www.crosswinds.net/~tok/tokrays.html


Post a reply to this message

From: H  E  Day
Subject: Re: I know this can not be a first
Date: 28 Sep 2000 16:30:53
Message: <01c0298a$cd22a7c0$3d7889d0@daysix>
Matt- 
I've posted in both p.b.i and p.b.s-f.  Take a look and tell me if these
help.  They mainly use material maps to achive an infinite detail level.
(two images posted in p.b.i: a far away view and a very close in view.  The
same model was used in both.)
I have in fact, zoomed all the way in, only a foot from the surface and
still the resulting render looked really good.


The Zip file in p.b.s-f is 25K in size and contains all files used.

Hope this helps.

H.E. Day
<><


Post a reply to this message

From: Matt Giwer
Subject: Re: I know this can not be a first
Date: 3 Oct 2000 02:55:21
Message: <39D982EA.FC80D139@ij.net>
"H. E. Day" wrote:
> 
> Matt-
> I've posted in both p.b.i and p.b.s-f.  Take a look and tell me if these
> help.  They mainly use material maps to achive an infinite detail level.
> (two images posted in p.b.i: a far away view and a very close in view.  The
> same model was used in both.)
> I have in fact, zoomed all the way in, only a foot from the surface and
> still the resulting render looked really good.
> 
> The Zip file in p.b.s-f is 25K in size and contains all files used.
> 
> Hope this helps.
> 
> H.E. Day
> <><

	If  you mean me, I need a bit more than that to find the posts. 

	Apologies. 

-- 
First they ignore you. Then they laugh at you. 
Then they fight you. Then you win. -- Ghandi
	-- The Iron Webmaster, 57


Post a reply to this message

From: Francois Labreque
Subject: Re: I know this can not be a first
Date: 3 Oct 2000 09:10:59
Message: <39D9D985.44931DD6@attglobal.net>
Matt Giwer wrote:
> 
> "H. E. Day" wrote:
> >
> > Matt-
> > I've posted in both p.b.i and p.b.s-f.  Take a look and tell me if these
> > help.  They mainly use material maps to achive an infinite detail level.
> > (two images posted in p.b.i: a far away view and a very close in view.  The
> > same model was used in both.)
> > I have in fact, zoomed all the way in, only a foot from the surface and
> > still the resulting render looked really good.
> >
> > The Zip file in p.b.s-f is 25K in size and contains all files used.
> >
> > Hope this helps.
> >
> > H.E. Day
> > <><
> 
>         If  you mean me, I need a bit more than that to find the posts.
> 
>         Apologies.

The titles are "for Matt Giwer".

... unless you have done like many other and killfiled yourself...

:)


> 
> --
> First they ignore you. Then they laugh at you.
> Then they fight you. Then you win. -- Ghandi
>         -- The Iron Webmaster, 57

-- 
Francois Labreque | And a four year old carelessly banging on a toy
     flabreq      | piano is not only 'music', it's probably the last
        @         | moment of 'artistic purity' they'll ever enjoy
  attglobal.net   | before outside influences start corrupting their
                  | expression.    - Chris R.


Post a reply to this message

From: Matt Giwer
Subject: Re: I know this can not be a first
Date: 2 Nov 2000 16:28:47
Message: <3A01DC8F.3255AC28@ij.net>
Francois Labreque wrote:
> 
> Matt Giwer wrote:
> >
> > "H. E. Day" wrote:
> > >
> > > Matt-
> > > I've posted in both p.b.i and p.b.s-f.  Take a look and tell me if these
> > > help.  They mainly use material maps to achive an infinite detail level.
> > > (two images posted in p.b.i: a far away view and a very close in view.  The
> > > same model was used in both.)
> > > I have in fact, zoomed all the way in, only a foot from the surface and
> > > still the resulting render looked really good.
> > >
> > > The Zip file in p.b.s-f is 25K in size and contains all files used.
> > >
> > > Hope this helps.
> > >
> > > H.E. Day
> > > <><
> >
> >         If  you mean me, I need a bit more than that to find the posts.
> >
> >         Apologies.
> 
> The titles are "for Matt Giwer".
> 
> ... unless you have done like many other and killfiled yourself...
> 
> :)

	Tried that once but beat myself at my own game. ;)

	Thanks.

-- 
If there are no races, how can there be racism? 
	-- The Iron Webmaster, 217


Post a reply to this message

Copyright 2003-2023 Persistence of Vision Raytracer Pty. Ltd.