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  Redux question on isosurfaces. (Message 1 to 4 of 4)  
From: CreeD
Subject: Redux question on isosurfaces.
Date: 7 Aug 2000 23:14:43
Message: <01c000e7$889cd9c0$041ba1d0@mk>
Thanks to all that replied (the bucky ball is neat T.O.C.) ...
let me rephrase my earlier question.

Is there a 'standard' way to take a pigment/normal such as marble, wood, or
basic checker-type patterns and make them not only *look* like a surface
normal
but to actually *be* a surface normal using isosurfaces?
The hexagon thing didn't work but I got it to sorta do what I was
expecting, in that
I ended up with a bunch of 3-D six-sided polygons extruding in the y
direction.

What would the code look like for a crackle sphere using isosurfaces?


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From: David Fontaine
Subject: Re: Redux question on isosurfaces.
Date: 8 Aug 2000 01:20:46
Message: <398F96B2.2D190421@faricy.net>
CreeD wrote:

> Thanks to all that replied (the bucky ball is neat T.O.C.) ...
> let me rephrase my earlier question.
>
> Is there a 'standard' way to take a pigment/normal such as marble, wood, or
> basic checker-type patterns and make them not only *look* like a surface
> normal
> but to actually *be* a surface normal using isosurfaces?
> The hexagon thing didn't work but I got it to sorta do what I was
> expecting, in that
> I ended up with a bunch of 3-D six-sided polygons extruding in the y
> direction.
>
> What would the code look like for a crackle sphere using isosurfaces?

#declare Normal = function { pigment { crackle } }
isosurface {
   function { sqrt(x^2+y^2+z^2)-1-Normal*.1 }
   ...
}

--
David Fontaine     <dav### [at] faricynet>     ICQ 55354965
Please visit my website: http://www.faricy.net/~davidf/


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From: Warp
Subject: Re: Redux question on isosurfaces.
Date: 8 Aug 2000 05:52:40
Message: <398fd868@news.povray.org>
CreeD <mes### [at] nqinet> wrote:
: Is there a 'standard' way to take a pigment/normal such as marble, wood, or
: basic checker-type patterns and make them not only *look* like a surface
: normal
: but to actually *be* a surface normal using isosurfaces?

  I think you have an erroneous terminology here.

  A normal pattern applied to a surface doesn't "look like a surface normal".
They are surface normals. There's no way a normal pattern could only "look
like" a surface normal without being it.
  That's what normal patterns do: They modify the surface normal.

  I think that you have mistaken the concept of "surface normal" and the
actual shape of the surface. A surface normal is used to simulate (fake) the
look of a shape on a straight surface, a shape which isn't really there, but
it looks like it is there because of lighting and shading.
  What you wanted was to get the actual shape of the surface and not only the
surface normal modifier.

  The only way I can think of faking a surface so that it looks like it has
a surface normal although it really hasn't, would be to create a pigment that
looks like it was shaded according to the light sources (of course it will
not work if the light sources move).

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):_;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/


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From: Phil Clute
Subject: Re: Redux question on isosurfaces.
Date: 9 Aug 2000 04:29:23
Message: <39911680.74029A34@tiac.net>
> What would the code look like for a crackle sphere using isosurfaces?

Try this...
http://www.econym.demon.co.uk/isotut/pigment.htm
Home  http://www.econym.demon.co.uk/isotut/index.htm
-- 
Phil
...coffee?...yes please! extra sugar,extra cream...Thank you.


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