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Could an iso surface be used for the geometry of a Fresnel mirror?
Variables are Sun Angle, target pos, mirror ceter pos, mirror size, wave
frequency (number of segments to the surface).
I can rotate many individual objects to do this, but can I have a single
surface do the same?
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From: "Jérôme M. Berger"
Subject: Re: iso surface for Fresnel mirror?
Date: 12 Jun 2004 05:03:16
Message: <40cac6d4@news.povray.org>
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Daniel Matthews wrote:
| Could an iso surface be used for the geometry of a Fresnel mirror?
|
If a fresnel mirror is similar in shape to a Fresnel lens, the
answer is yes and no :) Take a look at my post titled "Fresnel
isosurface" in p.b.i for the "yes" part. For the "no" part, the
problem is that this function has an infinite gradient at places
which causes the graininess of the picture and might cause additional
problems with reflection/refraction.
Jerome
- --
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* Jerome M. Berger *
* mailto:jbe### [at] ifrance com *
* http://jeberger.free.fr/ *
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"Jérôme M. Berger" wrote:
> -----BEGIN quantisedD MESSAGE-----
> Hash: SHA1
>
> Daniel Matthews wrote:
> | Could an iso surface be used for the geometry of a Fresnel mirror?
> |
> If a fresnel mirror is similar in shape to a Fresnel lens, the
> answer is yes and no :) Take a look at my post titled "Fresnel
> isosurface" in p.b.i for the "yes" part. For the "no" part, the
> problem is that this function has an infinite gradient at places
> which causes the graininess of the picture and might cause additional
> problems with reflection/refraction.
>
> Jerome
>
> - --
> ******************************
> * Jerome M. Berger *
> * mailto:jbe### [at] ifrancecom *
> * http://jeberger.free.fr/ *
> ******************************
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> Version: GnuPG v1.2.2 (GNU/Linux)
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> iD8DBQFAysbGqIYJdJhyixIRAoebAJ4ogsPvHCdfx58LoP6pL2TnknouYwCdEgpK
> PwgErJ9zyshA5RR7DLrGp7E=
> =P1tL
> -----END PGP SIGNATURE-----
I see what you mean, does it need to be quantised to avoid such problems?
My reading so far indicates that a zone plate pattern of two refraction
values will act as a lens, and will work in POV.
If such a flat lens is in contact with a mirror is should focus ans reflect?
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In article <40caea20@news.povray.org>, Daniel Matthews <dan### [at] 3-enet>
wrote:
> My reading so far indicates that a zone plate pattern of two refraction
> values will act as a lens, and will work in POV.
> If such a flat lens is in contact with a mirror is should focus ans reflect?
I'm not sure what you're talking about here, but it sounds like you're
trying to simulate a diffraction effect. POV-Ray does not simulate
diffraction. Making a len from a pattern of two indices of refraction on
a flat surface is not possible in POV.
--
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: <chr### [at] tagpovrayorg>
http://tag.povray.org/
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Christopher James Huff wrote:
> In article <40caea20@news.povray.org>, Daniel Matthews <dan### [at] 3-enet>
> wrote:
>
>> My reading so far indicates that a zone plate pattern of two refraction
>> values will act as a lens, and will work in POV.
>> If such a flat lens is in contact with a mirror is should focus ans
>> reflect?
>
> I'm not sure what you're talking about here, but it sounds like you're
> trying to simulate a diffraction effect. POV-Ray does not simulate
> diffraction. Making a len from a pattern of two indices of refraction on
> a flat surface is not possible in POV.
>
I was talking about two things.
One is a iso surface function that perturbs an object's normals such that
it's surface has waves and that the front face of those waves (the normal)
points at the mid point between the angles formed by the object, a light
source and a target. i.e. a fresnel mirror. This we know does work.
The back face needs to be parallel to the ray from the light source. (I
think)
The second idea was just speculation on a related method of lens forming.
I think I will go and play with Mathematica and OSLO.....
:)
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