Q. about MegaPOV Dispersion, and warning about an error in NewIOR.inc (Message 1 to 3 of 3)
From: Sven-Erik Andersen
Subject: Q. about MegaPOV Dispersion, and warning about an error in NewIOR.inc
Date: 25 Apr 2000 18:32:56
Message: <390617bf.657118766@204.213.191.228>
Haven't had much time to use it, but started to look through the docs
yesterday. And I have a question about dispersion. How do I calculate
the value if I have the IOR-value for both violet and red? Is it as
simple as IOR_Red/IOR_Violet?
Unfortunately, Daren's pages about it is unavailable for the moment.
I thought I would update the NewIOR.inc file for those minerals where
I have both IOR-values to include the dispersion values. I need to
update the file becouse of an error in it (line 129, Greenockite_IOR
should be :
#declare Greenockite_IOR = 2.50 + 2.52 / 2; // Cadmium Sulfide
Sven-Erik Andersen
----
sve### [at] andersenas
sea### [at] mailcitycom
http://www.geocities.com/SiliconValley/Program/2549/
From: Peter Popov
Subject: Re: Q. about MegaPOV Dispersion, and warning about an error in NewIOR.inc
Date: 25 Apr 2000 20:23:49
Message: <i6dcgscb4od5aqhffh6h8nheqfn8a70bev@4ax.com>
On Tue, 25 Apr 2000 22:32:57 GMT, sea### [at] mailcitycom (Sven-Erik
Andersen) wrote:
>Haven't had much time to use it, but started to look through the docs>yesterday. And I have a question about dispersion. How do I calculate>the value if I have the IOR-value for both violet and red? Is it as>simple as IOR_Red/IOR_Violet?
I would suggest you either e-mail Daren or conduct a test. Shoot a red
and a violet thin rays at a prism and see where they end after
refracting once by graduating the far side of the prism. One should be
able to calculate the relation between the value of dispersion and ior
or at least obtain an accurate enough linearisation of it.
Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] usanet
TAG e-mail : pet### [at] tagpovrayorg
From: Margus Ramst
Subject: Re: Q. about MegaPOV Dispersion, and warning about an error in NewIOR.inc
Date: 25 Apr 2000 23:45:57
Message: <390658B5.FA2CD8D5@peak.edu.ee>
Sven-Erik Andersen wrote:
> > the value if I have the IOR-value for both violet and red? Is it as> simple as IOR_Red/IOR_Violet?>
Whom what I've gathered from the scant documentation, that seems about right.
From the MegaPOV docs:
The dispersion value is the ratio of IOR values for violet to red. Good numbers
are 1.01 to 1.1. The IOR value given by the ior keyword is taken to be for
yellow-green, the color at the center of the spectrum.
--
Margus Ramst
Personal e-mail: mar### [at] peakeduee
TAG (Team Assistance Group) e-mail: mar### [at] tagpovrayorg
as
sea### [at] mailcity