"Andrew C on Mozilla" <voi### [at] devnull> wrote in message
news:409e26b3$1@news.povray.org...
> >>This is supposed to be a an extreme closeup of a small gemstone (a
> >>few mm across), set in a gold setting. But it looks nothing like
>  >>that - and I can't figure out why.
>  >>
> >>The stone doesn't look remotely gem-like. Can't figure that out.
> >>It's transparent, reflective, and reflective. What am I missing?
> >
> > Your gemstone needs facets on the back of the stone. Do a Google
> > search for 'Baguette Cut', 'Emerald Cut', and 'Princess Cut'.
You'll
> > see that your gemstone also needs to be shallower.
>
> ...so what you're saying is that it's all in the cut?

   Yes, normally. A diamond is the perfect example of refraction. I
forgot to say that you need more facets on the crown, (top, table), of
your gemstone too - depending on what cut you want.


>
> OK... well just Googling for (e.g.) Emerald Cut gives me a huge list
of
> shops that will *sell* me an emerald cut gemstone of one sort or
> another... I've found a few little black and white 2D outline
drawings
> and a few photos, but I can't find anything clear enough to make a
> POV-Ray model from.

     Hit 'Images' in Google for all of those terms...


>
> Anyone know where I can find technical drawings with measurements?
>
> >>The setting doesn't look like gold. I've fiddled with brilliance,
> >>specular, roughness, reflection, and turned on metallic (as well
as
> >>conserve_energy). Still doesn't look remotely like metal. Why?
> >
> >
> >     It looks like gold to me - it's not that bad, try turning the
> > ambient and reflection up a touch. The tips of your 'prongs' need
to
> > be bent over the stone too.
>
> I don't know... maybe the lighting is wrong... I already have 3
light
> sources, and still can't get it to look right.

   Well, with this reflective surface, you need the gold to reflect
*something*, so, put something behind the camera, put something above
the setting.

  Also, try this for a gold texture:

   texture {T_Gold_1A }

    finish {
        ambient 0.035
        diffuse .3
        brilliance 5
        phong 0.41
        phong_size 2}}



 Oh yes, and I know about
> the prongs - but I have no idea how to explain that to POV-Ray.

   I'm sure someone can tell you, but I don't know either!  :o/

>
> >    Perseverance!  ;)
>
> Well, this *is* the POV-Ray NG isn't it? ;-) LOL!

   It is??!  Sheesh! I've been coming to the wrong place all these
years!  :-O


   ~Steve~  ;)



>
> Andrew @ home.

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