Ken heeft geschreven in bericht <36F9FFD8.D4819465@pacbell.net>...
>Greetings Photon Phonatics !>
>  .............
>
>4.)  How do you force it to stop sending out so many photons ? ...........

Use autostop 0 in the global_settings
Don't start with a very small radius and density setting. Use only one or
two steps.

>5.)  If I collect more photons than I shoot does this indicate that I do
>   not have my gathering radius and/or the number of steps set correctly
>.....

No, I  think the settings are ok. Keep an eye on the priority queue remove
value, keep it close to zero.

>   .......or is this an ideal situation. It seems to me that in most cases
you
>   would seek to have shot more photons that the number gathered.

It seems to depend on the type of object (ior?) and the light position. A
light shining through a (converging) lens on a plane will gather lots of
photons. An object that diverges the light will gather less.

>7.) On the same topic as above should light bend in accordance with
>   the natural laws of physics or is the photon model used in the
>   patch more of a visual gimmick than a relativistic lighting model.
>   I have observed unnatural behaviour in three different prisms
>   constructed using differing methods. .......

Didn't try prisms yet, but for lenses and mirrors the patch behaves
accurate. You can build complete optical systems, use photons_pass_through
on every optical element except for the last. Only have the last element
generate the caustics. Every element should have the appropriate glass
texture and ior. Use a high setting for the max_trace_level (this also helps
against the black shadows in the glass with liquid scenes).
For prisms the problem will be the total internal reflections, as pointed
out by Mike.

>
>   That is all for now.
>
>   Thank you for your continued support.
>
>   Ken Tyler.

When I set up a one light, one object scene, in global_settings I set  the
photons radius to an angle of say 0.05 to start with. Then in the object I
set the density
to 0.1, followed by a test render. If queue remove value is high I make the
density value bigger. If the remove value is not shown I reduce the density
value. Make the remove value close to zero.
To change the quality (sharpness) of the caustics, devide (or multiply) the
radius and
density values by two. Then tweak again. The parse time and memory use will
go up, the rendertime will stay the same (almost)
Continue these steps until you are satisfied, run out of memory or until
UVPOV gives up (caustics are gone).
If you change the lightposition or the camera position much, you can start
tweaking again. Also when you change the properties of the
defracting/reflecting object (thickness of glass, ior).

Put "I think, ..." before and after everything I stated here.

ingo

--
Met dank aan de muze met het glazen oog.

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