Hi Dave,

If you're using the area_light keyword *inside* the photons block of your
light_source, that will cause artifacts in a lot of cases. Try disabling it
(you can leave it turned on in your native light_source for the soft
shadows) and you should lose the speckles.

Below is an excerpt from the pov-ray documentation (3.6.3.3 Photons FAQ,
second-last question):

"Photons do work with area lights. However, normally photon mapping ignores
all area light options and treats all light sources as point lights. If you
would like photon mapping to use your area light options, you must specify
the "area_light" keyword within the photons { } block in your light
source's code. Doing this will not increase the number of photons shot by
the light source, but it might cause regular patterns to show up in the
rendered caustics (possibly splotchiness)."

The last sentence is of interest, I think.


-- sooperFoX

"NetDave" <new### [at] netdavecom> wrote:
> Thanks for all the suggestions everyone. So far nothing has worked. I tried
> a bunch of other objects and they all seem to work ok. I guess I'll come
> back to this sometime, but for now the cone doesn't seem to want to
> cooperate. Lots of other shapes will make this scene work and I'll post it
> when I'm satisfied with the composition.
>
> -- Dave
>
> "NetDave" <new### [at] netdavecom> wrote in message
> news:46edc6c0@news.povray.org...
> > I'm sure this is a frequent problem, but I just can't find the information
> > in the documentation. I'm rendering this scene with photons and as you can
> > see in the attached image the returning rays through the cone are coming
> > back as speckles. I've tried some of the photon settings with no success.
> > Thanks for any suggestions.
> >
> > -- Dave

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