hi group,
could someone (Ken Maybe?) direct me to a good tutorial on the basics of
animating water with Pov? I am talking about ripples on a pond or waves in
an ocean.

thanks.
Steven

Post a reply to this message

Steven Durham wrote:
> 
> hi group,
> could someone (Ken Maybe?) direct me to a good tutorial on the basics of
> animating water with Pov? I am talking about ripples on a pond or waves in
> an ocean.
> 
> thanks.
> Steven

I know of no tutorials on this subject. Animating breaking waves on the ocean
is impossible near as I can tell ( too hard for me anyway) but swells and
ripples can be simulated using normals along with the "phase" keyword when
combined with a clock value. You will have to experiment to find values
that work with the scale of your scene and the properties you wish to impart
to them.

 Sorry for the vague reply but I don't do many animations and I have never
tried to animate water except for one attept using a very unortodox approach
using height fields to simulate water dropping onto the surface of a pool.

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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I concur.  Here is a simple code fragment that might help.  I'm sure
I stole it from someone else so I can't take credit, but it gives you
a starting point for using the clock as a phase modifier.  Looking at
the code again I can't think of a worse example, but you work with
what you have, right?  :-)

#declare Sea = plane {
    y, 0
    texture {
        T_Silver_1C
        normal {
            average
            normal_map {
                [ ripples 0.05 frequency 2 scale 0.05 translate <0, 0,
100000> phase ( clock * -3 ) ]
                [ ripples 0.15 frequency 3 scale 0.008 translate <0, 0,
10000> phase -clock ]
                [ waves 0.15 frequency 2 scale 0.05 translate <0, 0, 10000>
phase -clock ]
                [ wrinkles 0.25 scale 0.01 ]
                [ wrinkles 0.001 ]
            }
        }
    }
}

"Ken" <tyl### [at] pacbellnet> wrote in message
news:38877C7B.566F9E75@pacbell.net...
>
>
> Steven Durham wrote:
> >
> > hi group,
> > could someone (Ken Maybe?) direct me to a good tutorial on the basics of
> > animating water with Pov? I am talking about ripples on a pond or waves
in
> > an ocean.
> >
> > thanks.
> > Steven
>
> I know of no tutorials on this subject. Animating breaking waves on the
ocean
> is impossible near as I can tell ( too hard for me anyway) but swells and
> ripples can be simulated using normals along with the "phase" keyword when
> combined with a clock value. You will have to experiment to find values
> that work with the scale of your scene and the properties you wish to
impart
> to them.
>
>  Sorry for the vague reply but I don't do many animations and I have never
> tried to animate water except for one attept using a very unortodox
approach
> using height fields to simulate water dropping onto the surface of a pool.
>
> --
> Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
> http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

Steven Durham wrote:
> 
> hi group,
> could someone (Ken Maybe?) direct me to a good tutorial on the basics of
> animating water with Pov? I am talking about ripples on a pond or waves in
> an ocean.
> 
> thanks.
> Steven

Have a look at:

http://www.cstech.fr/~babin/babin/frames/frm-pov-en.htm

Gil Babin is a very good artist. It's really worth to look around there:

http://www.cstech.fr/~babin/babin/index.html


I hope this one helps,

Marc

-- 
Marc Schimmler

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On Thu, 20 Jan 2000 10:47:43 -0500, "Steven Durham"
<ste### [at] earthlinknet> wrote:

>hi group,
>could someone (Ken Maybe?) direct me to a good tutorial on the basics of
>animating water with Pov? I am talking about ripples on a pond or waves in
>an ocean.
>
>thanks.
>Steven

For a cheap and dirty solution you may use the ripple or waves normal
with phase hooked on the clock variable. You may use a normal_map
based on the cylindrical or spherical pattern to make them fade with
distance.

A little more complicated approach involves actual 3D modelling of the
ripples using an isosurface. You may use a function such as
sin(sqrt(x*x+z*z)) or directly a waves or ripple pattern. The
isosurface approach would require either of the Isosurface, Superpatch
or Megapov unofficial compiles.

Another approach would be (and I wonder why Ken, our resident hf
expert, missed it :) ) to use a height field. You can launch another
copy of POV-Ray before your scene (using the pre-frame shellout in the
INI file) to render the source image for the height field, which is
most easily done with an orthographic camera facing a plane of ambient
1 and a grayscale pigment such as ripples, waves, wrinkles, bumps or
some combination thereof.

The last, most physically correct, hardest and slowest to parse,
approach is to model the water surface by successively calculating
surface tension forces. Have a rectangular mesh of 100x100 points
(most easily done with a 100x100 array). Let the distance between two
adjacent points be 1 or sqrt(2) depending on the direction of
adjacance. Lastly, let each point pull the surrounding 8 points by
forces proportional to the respective distances to them. Now, apply a
disturbance in the mesh, for example move the central point 10 units
downward. Because all points interract with the ones surrounding them,
this model will reliably represent surface tension forces on a water
surface. So as you start rendering successive frames you'll see that
the mesh of points (render them using spheres or make a mesh object
out of them) will act as a real water surface. The disturbace of the
central point may represent the stone that causes the pond ripples.

Hope this hels some. Modelling water is no easy task and texturing
it... well, I'll let you find out by yourself if you haven't already
:)




Peter Popov
pet### [at] usanet
ICQ: 15002700

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Marc Schimmler wrote:

> Have a look at:
> 
> http://www.cstech.fr/~babin/babin/frames/frm-pov-en.htm

Yum ! A new link for the collection.

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

Peter Popov wrote:

> Another approach would be (and I wonder why Ken, our resident hf
> expert, missed it :) ) to use a height field.

Hey ! I did mention it if you re-read my reply. I just wasn't very
specific about the techniques :)

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

On Fri, 21 Jan 2000 01:34:58 -0800, Ken <tyl### [at] pacbellnet> wrote:

>
>
>Peter Popov wrote:
>
>> Another approach would be (and I wonder why Ken, our resident hf
>> expert, missed it :) ) to use a height field.
>
>Hey ! I did mention it if you re-read my reply. I just wasn't very
>specific about the techniques :)

I beg forgiveness mighty Ken!


Peter Popov
pet### [at] usanet
ICQ: 15002700

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Thanks Spock for the code fragment, it gives me a good place to start, and
thanks Mark for the great link. Peter, I can see I have a lot more studying
to do, I only understood about One word in three, but thanks for showing me
what to start studying

Steven


Peter Popov <pet### [at] usanet> wrote in message
news:WiyIOLGTsYsCD5t+rmHWRhodfe63@4ax.com...
> On Fri, 21 Jan 2000 01:34:58 -0800, Ken <tyl### [at] pacbellnet> wrote:
>
> >
> >
> >Peter Popov wrote:
> >
> >> Another approach would be (and I wonder why Ken, our resident hf
> >> expert, missed it :) ) to use a height field.
> >
> >Hey ! I did mention it if you re-read my reply. I just wasn't very
> >specific about the techniques :)
>
> I beg forgiveness mighty Ken!
>
>
> Peter Popov
> pet### [at] usanet
> ICQ: 15002700

Post a reply to this message

On Fri, 21 Jan 2000 08:51:00 -0500, "Steven Durham"
<ste### [at] earthlinknet> wrote:

>Thanks Spock for the code fragment, it gives me a good place to start, and
>thanks Mark for the great link. Peter, I can see I have a lot more studying
>to do, I only understood about One word in three, but thanks for showing me
>what to start studying
>
>Steven

I usually try to give a pointer rather than code or links. My online
time is limited and testing code or looking for links is hence not my
game. Besides, I think the best way to learn is by trying :) Therefore
I arranged the four options in my apply by increasing difficulty (ok,
someone may want to swap 2 and 3) so that when you inevitably want to
improve the look of your picture (there is no such thing as a
perfectly complete scene :) ) you may try another, harder (and
usually) and more realistic approach. This counts for many aspects of
POVing, as you will surely find out.

And Steven, we all have a lot more studying to do. Even if one excels
in POV (and I doubt there is anyone who can claim that :) ) there will
always be one more utility to try, patch to play with or just a new
technique to implement.

Feel free to ask for help whenever you think you need it, and happy
POVing.


Peter Popov
pet### [at] usanet
ICQ: 15002700

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