Of course it was only a joke ...

Yes dispersion and photons are features of MP...
They will probably render your image in about 24h ...

I just noticed, I'm working at 1152x864, so this size would be preferred ...
only some pixel more ;-)


--
plane{y,0 pigment{color rgb 1}}camera{location<1,5,-2>look_at
0}light_source{10 color 1}#macro m(a,b,c,n,i)#if(i=0)cylinder{a,b,c/3
pigment{color rgb z}}#else #local f=vlength(a-b)/32;#local d=(b-a)/8;#local
e=(vcross(d,n)/vlength(vcross(d,n)))*f*4;m(a-e,a+2*d+e,f,n,i-1)m(a+e,a+2*d-e
,f,n,i-1)m(a+3*d-e,a+3*d+e,f,n,i-1)m(a+3*d-e,a+5*d-e,f,n,i-1)m(a+6*d-e,a+6*d
+e,f,n,i-1)m(a+8*d-e,a+8*d+e,f,n,i-1)#end #end m(-4*x,2*x,1/8,y,4) // Jan
Walzer

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"Richard Morton" <rmm### [at] anywhereyoulike> wrote in message
news:3a90ebd1@news.povray.org...
>
> Does anyone remember the names of the different types of marbles and their
> relative values.
> - Ballbearings (metal both normal and dobber size)
>
>  Can anyone remember any other marble jargon ?

Although I played with marbles I remember little of the nomenclature about
them, however we called the ballbearings steelies.
About the rendering, I've always thought of the glass as being tinted green.
They look real good to me anyway, even if not fitting my idea of a marble
exactly.
Side note on marbles: I have 5 ceramic marbles that were excavated from the
1996 Olympic games site Atlanta, Georgia, USA where a marble factory existed
going back to the 1800's.   Maybe I should render them.
Having said that I did try to.  See attachment please.

Bob H.

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Attachments:
Download 'ceramic marbles.jpg' (24 KB)

Preview of image 'ceramic marbles.jpg'

The one on the right looks closest to a used marble.

From what I vaguely remember is that the marbles have the
green-glass-tint-look(absorbing media). When they're used a lot they get
tiny white chips resulting in a dirty-white or ash look. I also remember
marbles getting quite large chips in them, sometimes preventing from rolling
straight.

For the coloured swirls inside I'd suggest using then same index of
refraction as the glass to remove the 'bubble' look. Maybe something with a
bozo transparency might do the trick to get that blended look....

Nekar

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Francois Labreque wrote:
> The marbles found in aerosol paint cans look just like the one on the
> right.


What on earth possesed you to break open a can and find out ?


--
Duncan Gray
(warning: may contain traces of nut)

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Jan Walzer wrote:
> Yes dispersion and photons are features of MP...

Ah, I'll wait for POV 3.5 - got fed up with trying to convert all my Halo's,
so on the whole I prefer to stick to the current official version, and now
try to limit myself to what is finialised (as opposed to the 'warning this
may change' which I ignored to my peril with respect to the halo operation.

> I just noticed, I'm working at 1152x864, so this size would be preferred
...
> only some pixel more ;-)

No worries - my Compaq only needs it as 800x600, so the 1024x768 was going
to be 'by special request' anyway. It might take a little while but you'll
get it in the end.

Just noticed actually, my desktop needs it at 1152x864 as well.

--
Duncan Gray
(warning: may contain traces of nut)

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Setepenaset wrote:
> Those are nice. I've been trying to do a few marbles myself lately, but
> you're way ahead of me.

Your too kind - I'll post the source when done so you can see how I built
the twirly bits in the middle (blobs, basically) - the rest of it is pretty
straightforward - superellipsoids for the tiles (what else ?) and sphere's
for the marbles.

Having lots of fun with the normals at the moment.

Cheers

--
Duncan Gray
(warning: may contain traces of nut)

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David Fontaine wrote:
> I think the left one is much better. Glass is pretty resistant to
deformation,
> at a certain level of stress it'll just break.


Funny you should say that, I fiddled about with the one on the right that it
has now broken in half.

I guess the picture is now called " Red wins by K-O "


> From what I remember of my marbles, back before I lost 'em, the colored
part is
> much more two-dimensional. What I would do; imagine spinning a disc to
make a
> sphere, but instead of tracing out infinite copies of the disc, trace out
some
> number like three. Then take this whole thing and twist it around the same
axis
> you spun the disc around, so you get a multiple helix thing, with edges
along a
> sphere or ellipsoid.


Ah, so my memory wasn't lieing to me - the colours are more ribbon-like than
solid. At the moment I'm doing it by spinning three negative blobs about a
positive blob, then duplicating this shape, shorted but fatter and flipped
on it's axis of rotation. That way the colour on the top and bottom
inter-twines the color in the centre.

it might not be too much work to correct this (fatal last words).

Thanks V. much, I'll go back and play some more.

--
Duncan Gray
(warning: may contain traces of nut)

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Richard Morton wrote:
> These look very nice but the swirly coloured patterns (I'm trying to use
the
> correct terminology here) don't look like any marbles that I used in my
> youth. The patterns that I remember were more like leaves with two or
three
> twisted slightly.

Hmm, that seems to be the concensus of opinion, and is the next bit I'm
going to try and fix.

Richard Morton continued:
> Chips and scratches were very common, given that concrete and ashphalt
were
> the kinds of surfaces played on. The one on the right looks too severe,
the
> one on the left is better but probably needs more. I don't ever remember a
> marble breaking so they must have been very resistant to cracking.

Oh ... Mine just has; the marble on the right is now two semi-marbles.

Richard Morton concluded
> Does anyone remember the names of the different types of marbles and their
> relative values.

Probably different depending on where you are. in 1981, Reindahlen JHQ in
Germany, I think we called the white ones china-whites. The big ones we
called two-ers. One-ers for your regular marble. There were also some tiny
little ones I think we called pee-wee's. Ballbearings were called just that.
Don't recall what the totally transparent ones were called but I seem to
recall them being worth twice the normal value when it came to swapping,
etc. Ballbearings also were double the value of a like-sized marble as I
recall - might have been more.

We used to play marbles with holes (i.e. holes in the ground - like golf,
not holes in the marbles) Charlie Brown always seems to play marbles in a
big circle, I would figure the points value is based on this circle type
version of marbles. I beleive the name of the game with this form of marbles
is to shoot your marble, and attempt to knock the others out of the ring.
You win however many you knock out, so I would think the points value is
based in the weight of the marble. Shoot a heavier marble to increase your
chance of knocking more marbles out, but with the risk of loosing a higher
points value if it doesn't come out itself.

Phew, all this marble talk is bringing it flooding back

Cheers.

--
Duncan Gray
(warning: may contain traces of nut)

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Bob H wrote
> About the rendering, I've always thought of the glass as being tinted
green.
> They look real good to me anyway, even if not fitting my idea of a marble
> exactly.

I'd guess the colour would be down to low-quality glass, I imaging marble
factories buy the raw ... sand ? ... that is unsuitable for optical use.

> Side note on marbles: I have 5 ceramic marbles that were excavated from
the
> 1996 Olympic games site Atlanta, Georgia, USA where a marble factory
existed
> going back to the 1800's.

Any idea how they make them ? Glass marbles that is, not ceramic.

Thanks for your thoughts.

--
Duncan Gray
(warning: may contain traces of nut)

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Nekar Xenos wrote:
> For the coloured swirls inside I'd suggest using then same index of
> refraction as the glass to remove the 'bubble' look. Maybe something with
a
> bozo transparency might do the trick to get that blended look....

Ah, actually this effect was quite intentional, I thought they did have air
trapped in there alongside the swirls. I've done it by making the swirls
slightly reflective as opposed to adjusting the IOR, but it'll be easy to
remove.

Once I've got some ribbon-type swirls, I'll try rendering without. On this
swirl-model it looks a bit flat without the white highlights inside the
marble.

Thanks for your thoughts.


--
Duncan Gray
(warning: may contain traces of nut)

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