Ok, here's some things that've been bugging me about raytracing for a while
which might have simple work-arounds.

1.  Shadow fuzziness.  In the "real world", a shadow is nice and sharp when
    the object blocking the light is right next to the surface on which it
    is casting the shadow, and blurred as altitude above surface increases.
    In POV, the shadow is nice and sharp the whole way if default settings
    are used.  How to fix?

2.  Reflections in different type of materials.  With reflection, things
    like highly-polished metal reflect ad infinitum.  Things like lineoleum
    reflect things close to them, but become less reflective as object
    distance increases, with the exception of lighting.  This is not
    quite simply blurring the entire reflection, more like the reflection
    being 'foggy' (but not fading to a specific colour, instead fading to
    'nothing').  I suppose I could achieve this (somewhat) by making two
    renderings (one with fog, one without) and compositing them with the
    desired surfaces from the foggy one overlaid on the other, but it
    seems a hack.

3.  Concerning Media settings (and their application in, of all things,
    Moray).  Toying around with all the numbers is one thing.  Knowing
    what they do to get a desired result is entirely another.  Help!!!!
    Is there any documentation on what numbers in absorbsion/emission/
    scattering colours and sampling/confidence/variance/ratio produce
    good results to simulate specific media (i.e. undersea, dusty air)?
    There're too many variations to really approach it by making one
    rendering under each possibility to use as a reference.

I have yet to test POV3.5, which looks like it has some very cool new
features that I will probably need a faster computer to do as much as
I want with them (in my lifetime, at least...it always did impress me
the fact that POV can render just as complex a scene on a 386/33 as a
Pentium III/700 with the only difference being time, time, time...).

- T. Cook
http://empyrean.scifi-fantasy.com

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"Timothy Cook" <tim### [at] scifi-fantasycom> wrote in message
news:3B99A9F6.E0E5D4EC@scifi-fantasy.com...
> Ok, here's some things that've been bugging me about raytracing for a
while
> which might have simple work-arounds.
>
> 1.  Shadow fuzziness.  In the "real world", a shadow is nice and sharp
when
>     the object blocking the light is right next to the surface on which it
>     is casting the shadow, and blurred as altitude above surface
increases.
>     In POV, the shadow is nice and sharp the whole way if default settings
>     are used.  How to fix?

Try area lights

>
> 2.  Reflections in different type of materials.  With reflection, things
>     like highly-polished metal reflect ad infinitum.  Things like
lineoleum
>     reflect things close to them, but become less reflective as object
>     distance increases, with the exception of lighting.  This is not
>     quite simply blurring the entire reflection, more like the reflection
>     being 'foggy' (but not fading to a specific colour, instead fading to
>     'nothing').  I suppose I could achieve this (somewhat) by making two
>     renderings (one with fog, one without) and compositing them with the
>     desired surfaces from the foggy one overlaid on the other, but it
>     seems a hack.
>


Try Pov 3.5 fresnel reflection (read the docs for info on how it works) I've
been doing a lot of experimentation in this area lately.


-tgq

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Trevor Quayle wrote:
> "Timothy Cook" <tim### [at] scifi-fantasycom> wrote:
> > 1.  Shadow fuzziness.  [...]
> Try area lights

Also I see that ver 3.5 has soft lighting/shadow...perfecto!

Furthermore, the demo scenes 'optics' and 'dispersion-photons' leave me
absolutely breathless and drowning in drool...this is something I've been
dreaming of for a long time...(also I notice 3.5 is WAY faster with
renders than 3.1g...is there nothing this program can't do?! ^_^)

- T. Cook
http://empyrean.scifi-fantasy.com

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Timothy Cook <tim### [at] scifi-fantasycom> wrote:
:> Try area lights

: Also I see that ver 3.5 has soft lighting/shadow...perfecto!

  Note that area lights is not a new feature in 3.5. IIRC they have been
there at least from 2.2.

-- 
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -

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Warp wrote:
> 
> Timothy Cook <tim### [at] scifi-fantasycom> wrote:
> :> Try area lights
> 
> : Also I see that ver 3.5 has soft lighting/shadow...perfecto!
> 
>   Note that area lights is not a new feature in 3.5. IIRC they have been
> there at least from 2.2.

v3.0

-- 
Ken Tyler

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Timothy Cook wrote:
> 
> Ok, here's some things that've been bugging me about raytracing for a while
> which might have simple work-arounds.
> 
> 1.  Shadow fuzziness.

Area lights, as others have pointed out.

> 2.  Reflections in different type of materials.  With reflection, things
>     like highly-polished metal reflect ad infinitum.  Things like lineoleum
>     reflect things close to them, but become less reflective as object
>     distance increases, with the exception of lighting.

Blurred reflection. You might need MegaPOV for this; ISTR that blurring
was excluded from POV 3.5, in anticipation of a more comprehensive
texture/reflection/transparency/anything blurring solution, but I could
be wrong.

> 3.  Concerning Media settings (and their application in, of all things,
>     Moray).  Toying around with all the numbers is one thing.  Knowing
>     what they do to get a desired result is entirely another.  Help!!!!
>     Is there any documentation on what numbers in absorbsion/emission/
>     scattering colours and sampling/confidence/variance/ratio produce
>     good results to simulate specific media (i.e. undersea, dusty air)?

For most applications of media, you're probably better off using the new
media type in MegaPOV and POV 3.5; it gives fast smooth results without
needing to mess with the sampling settings, leaving you to figure out
how to best tweak the colors.

-Xplo

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