More tinkering around with the light/radiosity/focal blur.

A very simple image, with the following light.

light_source {
    <-0.5, 4.5, -0.5>
    color 0.1
    area_light <1, 0, 0>, <0, 0, 1>, 2, 2
    adaptive 1
    jitter
    fade_distance 12.0
    fade_power 3.0
    looks_like { sphere { <0.5,0,0.5>,0.5 } texture { pigment { color rgb
1.0 } finish { ambient 1.0 reflection 0.6 } } }
  }

Note the speckled zones around the shadows? What causes this and how can it
be eliminated? It shows up on the TGA as well as this JPG.

Post a reply to this message

Attachments:
Download 'camtest.jpg' (30 KB)

Preview of image 'camtest.jpg'

Try put (mutch)more lightsources in your arealight. it seems that the closer
the arealight is to the object the more sources are needed.

ingo

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

Charles Krause heeft geschreven in bericht <370e65e8.0@news.povray.org>...
>More tinkering around with the light/radiosity/focal blur.
>
>A very simple image, with the following light.
>
>light_source {
>    <-0.5, 4.5, -0.5>
>    color 0.1
>    area_light <1, 0, 0>, <0, 0, 1>, 2, 2
>    adaptive 1
>    jitter
>    fade_distance 12.0
>    fade_power 3.0
>    looks_like { sphere { <0.5,0,0.5>,0.5 } texture { pigment { color rgb
>1.0 } finish { ambient 1.0 reflection 0.6 } } }
>  }
>
>Note the speckled zones around the shadows? What causes this and how can it
>be eliminated? It shows up on the TGA as well as this JPG.
>
>
>
>
>

Post a reply to this message

Ingo's suggestion is the best and should eliminate much of this but you should
also try changing the adaptive setting up to around 5.

Charles Krause wrote:

> More tinkering around with the light/radiosity/focal blur.
>
> A very simple image, with the following light.
>
> light_source {
>     <-0.5, 4.5, -0.5>
>     color 0.1
>     area_light <1, 0, 0>, <0, 0, 1>, 2, 2
>     adaptive 1
>     jitter
>     fade_distance 12.0
>     fade_power 3.0
>     looks_like { sphere { <0.5,0,0.5>,0.5 } texture { pigment { color rgb
> 1.0 } finish { ambient 1.0 reflection 0.6 } } }
>   }
>
> Note the speckled zones around the shadows? What causes this and how can it
> be eliminated? It shows up on the TGA as well as this JPG.
>
>  [Image]

Post a reply to this message

Oh and a note though changing these setting will increase render time, depending
on how high you set them and the kind of scene you have. Play around with the
values to get the optimum tradeoff.

Thomas Lake wrote:

> Ingo's suggestion is the best and should eliminate much of this but you should
> also try changing the adaptive setting up to around 5.
>
> Charles Krause wrote:
>
> > More tinkering around with the light/radiosity/focal blur.
> >
> > A very simple image, with the following light.
> >
> > light_source {
> >     <-0.5, 4.5, -0.5>
> >     color 0.1
> >     area_light <1, 0, 0>, <0, 0, 1>, 2, 2
> >     adaptive 1
> >     jitter
> >     fade_distance 12.0
> >     fade_power 3.0
> >     looks_like { sphere { <0.5,0,0.5>,0.5 } texture { pigment { color rgb
> > 1.0 } finish { ambient 1.0 reflection 0.6 } } }
> >   }
> >
> > Note the speckled zones around the shadows? What causes this and how can it
> > be eliminated? It shows up on the TGA as well as this JPG.
> >
> >  [Image]

Post a reply to this message

Thomas Lake wrote in message <370E9E3C.E3EAFA83@home.com>...
>Oh and a note though changing these setting will increase render time,
depending
>on how high you set them and the kind of scene you have. Play around with
the
>values to get the optimum tradeoff.
>


Very much so!

I increased the number of elements in the light from a 2x2 array to a 10x10
array - and lost most of the shadow artifacts. It _quintupled_ the render
time however.

I don't know how much the increased adaptive jitter will increase the final
render time, as it's STILL rendering ;) On my lowley P133, it's rendering at
36 points per second!

One the other hand, so far the shadows look perfect using these two settings
in conjunction. I think a bit of light code like...

#declare final=0;

light_source {
                  <-0.5, 4.5, -0.5>
                  color <1,1,1>
                  area_light <1, 0, 0>, <0, 0, 1>, (final ? 2 : 10), (final
? 2 : 10)
                  adaptive (final ? 1 : 5)
                  jitter
                  fade_distance 12.0
                  fade_power 3.0
                  looks_like {
                                  sphere { <0.5,0,0.5>,0.5 }
                                  texture

                                             pigment { color rgb 1.0 }
                                             finish { ambient 1.0 reflection
0.6 }
                                             }
                                 }
                  }


Might be in order.

Thanks for everyone's input :)

Post a reply to this message

Charles Krause wrote:

> Thomas Lake wrote in message <370E9E3C.E3EAFA83@home.com>...
> >Oh and a note though changing these setting will increase render time,
> depending
> >on how high you set them and the kind of scene you have. Play around with
> the
> >values to get the optimum tradeoff.
> >
>
> Very much so!
>
> I increased the number of elements in the light from a 2x2 array to a 10x10
> array - and lost most of the shadow artifacts. It _quintupled_ the render
> time however.

Ya well 10x10 really is overkill for most images. Try a 5x5 array with adaptive
set to 5.

>
>
> I don't know how much the increased adaptive jitter will increase the final
> render time, as it's STILL rendering ;) On my lowley P133, it's rendering at
> 36 points per second!
>
> One the other hand, so far the shadows look perfect using these two settings
> in conjunction. I think a bit of light code like...
>
> Might be in order.
>
> Thanks for everyone's input :)

Welcome!

Post a reply to this message

>>
>> I increased the number of elements in the light from a 2x2 array to a
10x10
>> array - and lost most of the shadow artifacts. It _quintupled_ the render
>> time however.
>
>Ya well 10x10 really is overkill for most images. Try a 5x5 array with
adaptive
>set to 5.
>


I tried that first, but there were still shadow artifacts - that's why I
jumped it up to 10. Someone pointed out that the closer something is to the
array, the more elements are needed - and this scene is pretty compact.

Just for the hell of it, I added high-quality radiosity and a focal blur -
it's still rendering, but what I can see is _very_ realistic in quality. Of
course, it's 45% done, been rendering for 2 hours 28 minutes, while the
plain image without any of the bells and whistles, and a point light, takes
4 minutes :)

Post a reply to this message