Hi POVers!

See scene below.
First of all: I know, it's somehow a problem with max_trace_level and
my refracting sphere.
When I increase max_trace_level, I get less spots, but they don't
disappear, not at all.
Above max_trace_level 400, Povray crashes, but that's in the docs
(3.5docs : 6.11.7 the last paragraph). With m_t_l 400 there are many
black areas left.
Now, I don't understand, why Povray wants to shoot fourhundred rays
and more (in a row) in this sphere-inside. Maybe because of the total
reflection on the surface to the less denser medium. But those dots
are there with ior 1.01 - there shouldn't be much of total reflection.
I'm afraid I never want to use a normal{} with refracting objects,
because I know there always will appear those ugly dots. :-(
Can someone explain, or give hints, how to avoid them?

/// scene start
global_settings { max_trace_level 10 }

box {-9,9 pigment {color rgb 1}}

camera { location <-5,5,-5> look_at <0,0,0> }
light_source { 5 color rgb 1 }

sphere { <0,0,0>, 4
 pigment {color rgbt 1}
 normal { bozo .5 scale .5 }
 interior { ior 2 }
}
/// scene end

Thank you

cukk

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KalleK wrote:
> 
> Hi POVers!
> 
> See scene below.
> First of all: I know, it's somehow a problem with max_trace_level and
> my refracting sphere.
> When I increase max_trace_level, I get less spots, but they don't
> disappear, not at all.
> Above max_trace_level 400, Povray crashes, but that's in the docs
> (3.5docs : 6.11.7 the last paragraph). With m_t_l 400 there are many
> black areas left.
> [...]
> sphere { <0,0,0>, 4
>  pigment {color rgbt 1}

Totally transparent materials are quite seldom in the real world (if they
were possible, the world would have a max_trace_level problem too ;-), if
you decrease the transmit value just a little bit, the black spots
disappear with quite low max_trace_level.

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
IsoWood include, radiosity tutorial, TransSkin and other 
things on: http://www.schunter.etc.tu-bs.de/~chris/

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Or you can try to increase the adc_bailout.

--
Jonathan.
"Christoph Hormann" <chr### [at] gmxde> ha scritto nel messaggio
news:3BDBEB87.7A000F5D@gmx.de...
>
>
> KalleK wrote:
> >
> > Hi POVers!
> >
> > See scene below.
> > First of all: I know, it's somehow a problem with max_trace_level and
> > my refracting sphere.
> > When I increase max_trace_level, I get less spots, but they don't
> > disappear, not at all.
> > Above max_trace_level 400, Povray crashes, but that's in the docs
> > (3.5docs : 6.11.7 the last paragraph). With m_t_l 400 there are many
> > black areas left.
> > [...]
> > sphere { <0,0,0>, 4
> >  pigment {color rgbt 1}
>
> Totally transparent materials are quite seldom in the real world (if they
> were possible, the world would have a max_trace_level problem too ;-), if
> you decrease the transmit value just a little bit, the black spots
> disappear with quite low max_trace_level.
>
> Christoph
>
> --
> Christoph Hormann <chr### [at] gmxde>
> IsoWood include, radiosity tutorial, TransSkin and other
> things on: http://www.schunter.etc.tu-bs.de/~chris/

Post a reply to this message