POV-Ray : Newsgroups : povray.advanced-users : Why don't shadows get blurry after a certain distance? ("Distance Field Sha= : Re: Why don't shadows get blurry after a certain distance? ("Distance Field= Server Time
5 Jul 2022 04:49:47 EDT (-0400)
  Re: Why don't shadows get blurry after a certain distance? ("Distance Field=  
From: And
Date: 6 Jun 2022 03:50:00
Message: <web.629db0bb79b4ae9c11d6faaaa81652d@news.povray.org>
"HackerDaGreat57" <Hac### [at] gmailcom> wrote:
> "Bald Eagle" <cre### [at] netscapenet> wrote:
> > "HackerDaGreat57" <Hac### [at] gmailcom> wrote:
> >
> > > Is it possible to change the 'Radius' of the point light? Like in Blender's
> > > Cycles for example, there is an option to change the point light's radius which
> > > increases the 'amount' of penumbra on my shadows.
> > >
> > > Thanks anyway for the useful reference though.
> >
> > Not in the way you're asking.
> > But maybe another way.
> >
> > If you create a sphere with an emissive finish, then you could make a scene
> > using radiosity, and that might work in the way you want it to.
> >
> > You can also add no_image to the object definition so that it doesn't show up in
> > the scene, if it's in the camera's view frustum.
> That would, in fact, work like a charm.
> Do emissive materials count as light sources? (I'm concerned about the 127 light
> limit)

You can use an object with texture{ finish{emission 1.0}} instead of regular
light_source, when the radiosity turn on.
But, you need very high radiosity quality settings, especially "error_bound", or
you will get a very blurred shadow without accuracy created by radiosity.

The accuracy will establish when error_bound is very small. But at this time you
need high "count" to eliminate spotted result.

 pretrace_start 64/image_width
 pretrace_end   4/image_width

 count 160
 nearest_count 2
 error_bound 0.28      // this should be smaller
                       // if you use radiosity emission
                       // as a light source
 recursion_limit 4
 low_error_factor 0.5
 gray_threshold 0.0
 brightness 1.0         // brightness 1 is natural correct
 media off


radiosity {} block place in the global_settings{}

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