This time, the URL really *does* say it all!

http://en.wikipedia.org/wiki/Negative_refractive_index

Mmm, I wonder if POV-Ray can do this?

Post a reply to this message

> This time, the URL really *does* say it all!
> 
> http://en.wikipedia.org/wiki/Negative_refractive_index
> 
> Mmm, I wonder if POV-Ray can do this?

I remember somebody who was involved in the development of such 
materials, and was asking on these newsgroups if POV-Ray could simulate 
it. People weren't even sure what a negative index would look like, and 
POV didn't either :)

Post a reply to this message

Nicolas Alvarez wrote:

>> This time, the URL really *does* say it all!
>>
>> http://en.wikipedia.org/wiki/Negative_refractive_index
>>
>> Mmm, I wonder if POV-Ray can do this?
> 
> I remember somebody who was involved in the development of such 
> materials, and was asking on these newsgroups if POV-Ray could simulate 
> it. People weren't even sure what a negative index would look like, and 
> POV didn't either :)

Yeah, I would think this is likely to freak POV-Ray out a bit...

According to Wikipedia's diagrams, such a material "reflects" light, but 
with the angle of reflection NOT equal to the angle of incidence (as in 
normal reflection), but computed by Snell's law instead (as per normal 
refraction).

Damn weird if you ask me...

Also, apparently some materials have an IOR of less than 1. (E.g., 
0.98.) But not for optical wavelengths.

Post a reply to this message

Invisible <voi### [at] devnull> wrote:
> Mmm, I wonder if POV-Ray can do this?

  Probably not. AFAIK povray has a very specific refraction formula, which
it converts to total internal reflection when needed. I'm all but certain
that this formula does not support the concept of negative IOR.

-- 
                                                          - Warp

Post a reply to this message

Invisible nous apporta ses lumieres en ce 2007/11/07 10:59:
> Nicolas Alvarez wrote:
>> Invisible escribió:
>>> This time, the URL really *does* say it all!
>>>
>>> http://en.wikipedia.org/wiki/Negative_refractive_index
>>>
>>> Mmm, I wonder if POV-Ray can do this?
>>
>> I remember somebody who was involved in the development of such 
>> materials, and was asking on these newsgroups if POV-Ray could 
>> simulate it. People weren't even sure what a negative index would look 
>> like, and POV didn't either :)
> 
> Yeah, I would think this is likely to freak POV-Ray out a bit...
> 
> According to Wikipedia's diagrams, such a material "reflects" light, but 
> with the angle of reflection NOT equal to the angle of incidence (as in 
> normal reflection), but computed by Snell's law instead (as per normal 
> refraction).
> 
> Damn weird if you ask me...
> 
> Also, apparently some materials have an IOR of less than 1. (E.g., 
> 0.98.) But not for optical wavelengths.
A wave guide have ior <1 for radio waves. You can't find the equivalent for IR 
and visible light.
POV-Ray accept dispersion <0, but render the object as a mirror.
Try ior = -1.5 VS. 1.5... and the result is: (At least, it don't choke on this.)
Strange looking, unintuitive, but it work. I realy can't say if what I get is 
physicaly acurate, as I don't have anything to compare to.

-- 
Alain
-------------------------------------------------
   My wife likes to talk on the phone during sex; she called me from Chicago 
last night.
	Rodney Dangerfield

Post a reply to this message

Invisible wrote:
> This time, the URL really *does* say it all!
> 
> http://en.wikipedia.org/wiki/Negative_refractive_index
> 
> Mmm, I wonder if POV-Ray can do this?
I think I remember someone doing it a few years ago. It did produce 
something like fur or so. Or am I mixing things up? ...

In p.b.i. there is a thread about 'fur and negative ior' of Swen Heinzel 
  dated march 21st 2002. Seems like I am indeed confusing some things. ;)

Post a reply to this message

Warp wrote:
> Invisible <voi### [at] devnull> wrote:
>> Mmm, I wonder if POV-Ray can do this?
> 
>   Probably not. AFAIK povray has a very specific refraction formula, which
> it converts to total internal reflection when needed. I'm all but certain
> that this formula does not support the concept of negative IOR.

That was more or less my diagnosis, yes. ;-)

It's not something any typical implementation would support unless the 
designer purposely had this in mind, I would think.

Now negative light sources........ ;-)

Post a reply to this message

> Now negative light sources........ ;-)

You never tried it? It's fun. The shadows are brighter than the lit areas :)

Post a reply to this message

> This time, the URL really *does* say it all!
>
> http://en.wikipedia.org/wiki/Negative_refractive_index
>
> Mmm, I wonder if POV-Ray can do this?

Wow that's something to think about.  It was only a few years ago I learned 
that the refractive index is actually a complex number, useful when working 
with things like polarisers and (liquid) crystals that do funky things to 
the light.

Post a reply to this message

Invisible <voi### [at] devnull> wrote:
> This time, the URL really *does* say it all!
>
> http://en.wikipedia.org/wiki/Negative_refractive_index
>
> Mmm, I wonder if POV-Ray can do this?

sure:
http://www.opticsexpress.org/abstract.cfm?id=88325

Christoph Hormann, long contributor to povray, is one of the authors.
http://www.imagico.de/

Post a reply to this message