news:3c90dd01@news.povray.org...

> Hm. maybe I am wrong but look at the girdle: the bows caused by the round
> shape beeing cut by plain facets. This is created very easily by simply
> cutting a cylinder (which is in fact more realistic to the real creation
> process). Modelling this with a mesh while considering different
proportions
> and cut-types is not that easy (but of course not impossible).

So there are round shapes on the diamond? If this is the case you are
definitely correct. CSG is not only easier, but also provides the true round
edges needed for super-close inspection and certain interiors.

 -Shay

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> So there are round shapes on the diamond? If this is the case you are

Yes. The gridle. It is always round, mostly circular.

> definitely correct. CSG is not only easier, but also provides the true
round
> edges needed for super-close inspection and certain interiors.

Of course, since an ideal diamond is totally clear you can't really see the
difference between the round shaped CSG and a less-round shaped mesh. Maybe
some strange effects due to interior but no one really can tell since there
are so many caustic effects....

However, it was soooo simple to model as a CSG, I simply couldn't resist :-)

regards
SY

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Shay wrote:
> 

> news:3c9086ee$1@news.povray.org...
> >
> > maybe I'll implement the
> > emerald as well...
> >
> 
> You've got bragging rights if you can get the color and interior correct.
> 
> How is CSG be more suited to this than a mesh? Do you have a web reference
> for the shape of this cut? Because I am curious to see what you mean.

You'll find several POV-diamond images and links
to web pages about diamond cuts if you traverse
the threads that this search will list:

http://news.povray.org/search/?s=Diamond


Tor Olav

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> You'll find several POV-diamond images and links
> to web pages about diamond cuts if you traverse
> the threads that this search will list:
>
> http://news.povray.org/search/?s=Diamond


*lol* it seems that diamonds are traced approx. 10 times a year *g*
I didn't know that diamonds are so popular :-)

Well: my story is: I was looking for something completely different (already
forgot what exactly) and fell over a diamond-ideal-cut-property-picture
showing exact properties of the thing. It was interesting and so I continued
looking for exact physical properties of a diamond (especially IOR) which I
found rather quickly.
You can imagine the rest :-)

BTW: most pictures I saw in these threads were pretty deep cuts which don't
reflect properly. Strange. Either all made the same mistake or they all used
the same model?

regards
SY

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> 
> > You'll find several POV-diamond images and links
> > to web pages about diamond cuts if you traverse
> > the threads that this search will list:
> >
> > http://news.povray.org/search/?s=Diamond
> 
> *lol* it seems that diamonds are traced approx. 10 times a year *g*
> I didn't know that diamonds are so popular :-)

Yes, as many other topics it seems that
diamonds reappear quite often in these
groups.


> Well: my story is: I was looking for something completely different (already
> forgot what exactly) and fell over a diamond-ideal-cut-property-picture
> showing exact properties of the thing. It was interesting and so I continued
> looking for exact physical properties of a diamond (especially IOR) which I
> found rather quickly.
> You can imagine the rest :-)

I find the diamonds shapes and their internal
reflections very interesting. So I hope I soon
can find time to make some more diamond images.
(But there are so many other POV experiments
that I just have to do first...)


Here are IOR's for many real-world materials:

http://news.povray.org/povray.binaries.utilities/15777/
news://news.povray.org/b8a72tkp5bki1eatfm49cvb7729bmop43j%404ax.com

IOR_Isotropic.inc has IOR values for diamonds


> BTW: most pictures I saw in these threads were pretty deep cuts which don't
> reflect properly. Strange. Either all made the same mistake or they all used
> the same model?

It has been a while since I worked with
"perfect cut" diamond shapes, so I don't
quite remember if I was totally satisfied
with my shapes.

Btw.: Are you really sure that the girdle
lines should be "roundish" ?


Tor Olav

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Hi,

> can find time to make some more diamond images.
> (But there are so many other POV experiments
> that I just have to do first...)

Even more diamonds?? *lol*

> Here are IOR's for many real-world materials:

Thanks!

> Btw.: Are you really sure that the girdle
> lines should be "roundish" ?

Yes.

regards
SY

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> You've got bragging rights if you can get the color and interior correct.

BTW: you got me wrong. Read the subject before the text. The "good job" was
NOT meant for the diamond but for the PoV/MegaPoV DEVELOPERS.

All clear?

regards
SY

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news:3c91ed34$1@news.povray.org...
> > You've got bragging rights if you can get the color and interior
correct.
>
> BTW: you got me wrong. Read the subject before the text. The "good job"
was
> NOT meant for the diamond but for the PoV/MegaPoV DEVELOPERS.
>


I'm clear. I understand that you were not bragging about the diamond.
I meant what I said, though. Creating a convincing emerald material would be
a serious accomplishment, and worth bragging about.
 -Shay

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> And there we go again:  gimme code, gimme code, gimme code...   ;-)

just posted in p.b.s-f
regards
SY

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In article <3C9### [at] hotmailcom>,
 Tor Olav Kristensen <tor### [at] hotmailcom> wrote:

> Here are IOR's for many real-world materials:
> 
> http://news.povray.org/povray.binaries.utilities/15777/
> news://news.povray.org/b8a72tkp5bki1eatfm49cvb7729bmop43j%404ax.com
> 
> IOR_Isotropic.inc has IOR values for diamonds

The standard include consts.inc also has several iors, it has been 
updated for 3.5.

-- 
Christopher James Huff <chr### [at] maccom>
POV-Ray TAG e-mail: chr### [at] tagpovrayorg
TAG web site: http://tag.povray.org/

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