Re: Where does the black come from? (prism.jpg 320x240) (Message 1 to 3 of 3)
From: Mick Hazelgrove
Subject: Re: Where does the black come from? (prism.jpg 320x240)
Date: 4 Dec 1999 05:17:42
Message: <3848ea46@news.povray.org>
Yep I've had this before it is due, I believe to ior (internal
refraction?)and there is no solution.
Mick
SamuelT. <STB### [at] aolcom> wrote in message
news:384896EB.A252036E@aol.com...
> Has anyone else noticed this? You make a transparent object with> reflection and ior, and somehow it seems to refract black areas of> color. There are no such black spaces in my scene as far as I can tell.> Anyone know what's up with this?>> --> Samuel Benge>> E-Mail: STB### [at] aolcom>> Visit the still unfinished isosurface tutorial:> http://members.aol.com/stbenge>>
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From: anton sherwood
Subject: Re: Where does the black come from? (prism.jpg 320x240)
Date: 31 Dec 1999 21:46:42
Message: <386D6A56.BF98BCE8@pobox.com>
> > Ken wrote:> > > max_trace_level ?
Remco de Korte wrote:
> Couldn't it be that this won't help because internal reflection> goes on infinitely (until POV-Ray decides it's enough and decides> the pixel should be black)?
It would take quite a perverse shape to produce infinite internal
reflexion; sooner or later you're likely to hit a surface at near enough
to the normal to escape.
I usually set maxtrace to some arbitrary number like 256, but make sure
all transmit/reflection values are <1. If for example these are 3/4, we
reach the epsilon limit in 20 steps.
--
"How'd ya like to climb this high without no mountain?" --Porky Pine
Anton Sherwood *\\* +1 415 267 0685 *\\* http://www.jps.net/antons/
From: anton sherwood
Subject: Re: Where does the black come from? (prism.jpg 320x240)
Date: 31 Dec 1999 21:53:15
Message: <386D6BE5.689E6FD3@pobox.com>
> > Probably from total internal reflection.
David Fontaine wrote:
> I thought POV didn't do that...
Well, that would account for black areas.
By the way, I got some interesting effects with ior <1, not to mention <0!
--
"How'd ya like to climb this high without no mountain?" --Porky Pine
Anton Sherwood *\\* +1 415 267 0685 *\\* http://www.jps.net/antons/