On Fri, 15 Dec 2000 22:03:46 -0500, Chris Huff wrote:

>It's not that hard...it's a pretty simple function, made of even simpler 
>pieces.

Take no notice of him, he always says that.

>The full equation is:
>1/(sqr(x)+sqr(z)+0.3) + sin(atan2(x,z)*7 + y*10)*0.025 = 0

I rest my case.

-- 
Cheers
Steve              email mailto:ste### [at] zeroppsuklinuxnet

%HAV-A-NICEDAY Error not enough coffee  0 pps. 

web http://www.zeropps.uklinux.net/

or  http://start.at/zero-pps

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Chris Huff wrote:
> function {
>     1/(sqr(x)+sqr(z)+0.3) + sin(atan2(x,z)*7 + y*10)*0.025
> }

Ingenious.  I wonder how close to reality it is.


-- 
Anton Sherwood  --  br0### [at] p0b0xcom  --  http://ogre.nu/

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Anton Sherwood wrote:
> 
> >     1/(sqr(x)+sqr(z)+0.3) + sin(atan2(x,z)*7 + y*10)*0.025
> > }
> 
> Ingenious.  I wonder how close to reality it is.
> 

The 1/r function is probably quite near to reality, although i'm not
totally sure and it's usually rounded at the bottom.  The 'atan2' part is
maybe not that realistic, because such flows use to contain a lot of
turbulence leading to a more irregular pattern.  

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
IsoWood include, radiosity tutorial, TransSkin and other 
things on: http://www.schunter.etc.tu-bs.de/~chris/

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Great, please let us know when it's up and running!

> 
> thats the idea behind povray.co.uk - a functions section is now in the 
list
> of things to do
> 
> 
> --
> Rick
>

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In the mean time, have a heart :)

function {
(x^2+y^2+z^2+2*y-1)*((x^2+y^2+z^2-2*y-1)^2-8*z^2)+16*x*z*(x^2+y^2+z^2-2*y-1)
}

;)

--
Lance.

http://come.to/the.zone

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In article <3A3C7E22.B67C37A0@gmx.de>, Christoph Hormann 
<chr### [at] gmxde> wrote:

> The 1/r function is probably quite near to reality, although i'm not
> totally sure and it's usually rounded at the bottom.  The 'atan2' part is
> maybe not that realistic, because such flows use to contain a lot of
> turbulence leading to a more irregular pattern.  

This function is actually 1/(r^2 + n), the "+ n" part gives it the 
rounded bottom you were talking about. I would be very surprised if it 
was actually close to describing reality, I just made it to *look* real.

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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In article <MPG.14a57ca52986461b98985d@news.povray.org>, 
jam### [at] dh70qdu-netcom (Jamie Davison) wrote:

> <foetal position>
> <Whimper>
> Make the bad man go away mommy...
> <shake>

Heh heh heh....

function {((cos(sqrt(x*x+z*z)) - y*y))}

function {((cos(sqrt(x*x+z*z))+cos(y) - y*y))}

function {sqrt(sqr(x) + sqr(y-sqrt(sqr(x/2)+sqr(z/2))*1.5) + sqr(z)) - 1 
- (sin(atan2(x, z)*Ridges)*0.5*RidgeDepth)}

function {sqrt(x*x + z*z) + cos(abs(y/4))*2 - 2 - noise3d(x*0.5, y*0.2, 
z*0.5)*0.75 - noise3d(x*0.25, y*0.05, z*0.45) - noise3d(x*4, y, 
z*4)*0.05}

function {sqrt(x^2 + y^2 + z^2) - 1 - abs(sin(TH(x, y, z) + 
(PI*12*atan(sqrt(x^2 + z^2)/y))))*abs(sin(atan(sqrt(x^2 + 
z^2)/y)*15))&(-y +0.01)}

function {A*x + B*y + C*z + ((-1*cos(sqrt(x*x + 
z*z)*1.5))/(sqrt(x*x+1+z*z)/5) + (noise3d(x*0.25, y*0.25, z*0.25) + 
noise3d(x*0.2, y*2, z*2)*0.075)*2)}

Had enough? I've got many more where those came from...some even longer. 
:-)

Seriously, these functions are made of pretty basic pieces...once you 
understand them, making things like this isn't difficult. And for a lot 
of things, you just need to know some basic equations and what the 
graphs of the other functions look like.

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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Chris Huff wrote:
> 
> Heh heh heh....
> 
> [...]
> 
> Had enough? I've got many more where those came from...some even longer.
> :-)
> 

I think there is a limit for complexity of a single function (not sure
what exactly it is but i touched it some times. Anyway you can always
split up the function into several parts.   

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
IsoWood include, radiosity tutorial, TransSkin and other 
things on: http://www.schunter.etc.tu-bs.de/~chris/

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In article <3A3E45CA.6F04FD10@gmx.de>, Christoph Hormann 
<chr### [at] gmxde> wrote:

> I think there is a limit for complexity of a single function (not sure
> what exactly it is but i touched it some times.

Yes, the "parser is bored" error...


> Anyway you can always split up the function into several parts.  

I usually do that anyway, to make sure *I* don't get bored trying to 
read it...in addition, if the function repeats many times, putting the 
repetitive portion in a separate function could make an optimization 
possible in some future version...

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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On Sun, 17 Dec 2000 20:34:15 -0500, Chris Huff wrote...

[Much scary stuff snipped]

<fingers in ears>
La la la la la la la la...  I can't hear you...  la la la la la la...

And I'll stop this now, as it's starting to get more than a tad off 
topic, and I don't frequent p.o-t any more.

Bye for now,
     Jamie.

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