Here's some more Geomag things, this time in a different setting.

The problem with reflective objects is that you need something behind 
the camera to be reflected, and I'm just too lazy. I have created a very 
simple room, few of the objects have any detail in them as they're not 
meant to be seen directly. It could probably do with some more things in 
the room.
There are 2 area lights, 1 spherical one inside a blue lampshade and one 
outside a window illuminating some closed red curtains. Radiosity does a 
good job of filling the scene with light. It took nearly a day to render 
at 2560x1440.

On the left is an icosahedron, with points added. I think I should have 
stuck to plain colouring, it's a bit too busy.
Next is a double sized icosahedron in 3 colours to show up some of the 
symmetry.
The next object is the same, but with different colours and the 
pentagonal points turned inside out to form an icosidodecahedron.
Sticking some points on it results in one on my favourite Geomag shapes, 
here on the right. It uses 180 rods and 62 balls.

I think it's worth noting that if you scale the second shape up to being 
3 rods along each edge, and turn the pentagonal points inside out, you 
end up with a Geomag representation of the buckyball! 270 rods and 92 
balls required.

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Hey Alex, looks very believable (realistic) to me. Especially like your 
concept of using magnetic objects that add a sense of dynamics to these 
things.

I don't suppose you've gone so far as to add motion to the pieces so it 
could animate? This series of similar yet different shapes made me think 
that might be plausible-- except possibly a little difficult.

Sorry that I can't remember how you went about creating these. I saw an 
earlier picture or two, though.

Bob

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Alex wrote:
 >

Attractive models. Are those posts copied from some construction kit. 
Something looks familiar.

  -Shay

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In message <42f01389$1@news.povray.org>, Shay <dd### [at] dddd> writes
>Alex wrote:
>>
>
>Attractive models. Are those posts copied from some construction kit. 
>Something looks familiar.
>
Yes, it's called "Geomag".   http://www.geomagsa.com/

But I changed the name moulded into the rods to "MAGNET".
-- 
Alex

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In message <42eec1cf$1@news.povray.org>, Bob Hughes 
<omniverse@charter%net.?.invalid> writes
>Hey Alex, looks very believable (realistic) to me.

Thanks.

>Especially like your
>concept of using magnetic objects that add a sense of dynamics to these
>things.
>
>I don't suppose you've gone so far as to add motion to the pieces so it
>could animate? This series of similar yet different shapes made me think
>that might be plausible-- except possibly a little difficult.
>
They can be made to move. Depending on how many north or south poles are 
attached to each sphere, the spheres become magnetised themselves (not 
permanently). Smaller shapes can then be hung from another similarly 
magnetised sphere, which are then free to spin. It is possible to hang 
such shapes inside larger ones, but then the magnetic fields around the 
two shapes can interact unpredictably as the smaller shape spins.
Much easier to hold 1 rod in the air with a sphere stuck on one end, and 
hang the shape off that.

See http://www.geomagsa.com/cp_gioco.php?PageNum=3#su

Most regular shapes have some or all spheres with an odd number of rods 
attached, so it is impossible to balance the number of north and south 
poles to achieve no net magnetisation. So these shapes can have a 
complex magnetic field around them.
In fact the shape on the far right made a right mess of the picture on 
my monitor when I had it sat on my desk to study.

As for animating it in PovRay, It's possible. I'd have to give up the 
blurred reflections and area lights to reduce rendering times.
But I'm lazy, and I've got a couple of other things I'd like to try out 
as well as maybe some larger/more complex Geomag shapes.

I have thought about building a simple electronic circuit to switch some 
small electromagnets in sequence, in order to automatically spin such a 
shape. But I would have to re-wire it to change the sequence for 
different shapes.

>Sorry that I can't remember how you went about creating these. I saw an
>earlier picture or two, though.
>
I just calculate (almost by hand - I haven't written any clever programs 
or macros to do this) the co-ordinates of the balls. Then I have 2 
macros to place the parts. "placeball" takes a single co-ordinate, and 
puts a sphere there. "placerod" takes 2 co-ords and a texture index. It 
checks that the co-ords are the correct distance apart, and sticks a rod 
between them allowing space for where the balls go. The longitudinal 
rotation of the rod is random, and the texture index refers to one of 9 
rod textures (3 of which I made up). The silver-metallic one is a pig, 
it's clear plastic showing the central metal pin.
-- 
Alex

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