Hi,
I was playing around with skies (eventually i gave up for now), and then 
used the scene to play with post-proccesing in MegaPov, specifically 
soft glow and focal blur.
The island has jagged edges, due to one of the post-proccesors.
How is it?

btw, what's the difference between the post-procces focal blur and the 
official pov focal blur?

Enjoy!

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>btw, what's the difference between the post-procces focal blur and the
>official pov focal blur?


One is fast, the other is slow. :)

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"TonyB" <ben### [at] panamac-comnet> wrote in message
news:38e7e314@news.povray.org...
| >btw, what's the difference between the post-procces focal blur and the
| >official pov focal blur?
|
|
| One is fast, the other is slow. :)
|

I was going to say that.
The focal blur must be similar somehow to the camera blurring way, not
conventional AA.  That could be what goes wrong with it I guess, the camera blur
method still does an AA on even the sharp focus but the post process seems to
remove any AA which was done, or at least cause a backward step.  No doubt
because that process uses only the 3D info and not the pixel sampling.  That's
the way I figure it.

Bob

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TonyB <ben### [at] panamac-comnet> wrote:
:>btw, what's the difference between the post-procces focal blur and the
:>official pov focal blur?

: One is fast, the other is slow. :)

  That's not the only difference.
  The post-processing focal blur uses only the calculated pixel colors to
calculate the blurring and thus doesn't add any new information to the
image.
  The focal blur calculated while rendering is more accurate and can add
information to the image which would be invisible without focal blur (or
with post-processed focal blur).

  For example, consider the following scene:
  We have a red box in front of the camera and a green box just behind the
red one so the edge of the green box is just behind the edge of the red box,
so that the green box is not seen (but moving the camera just a bit will
make the edge of the green box to be seen behind the red box).
  Now, using post-processing focal blur will not make any part of the green
box visible, but using povray's focal blur can make the edge of the green
box a bit visible (depending on the location of the focal point, of course).
  Thus, povray's focal blur is physically more accurate.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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Bob Hughes <omn### [at] hotmailcom?subject=PoV-News:> wrote...
> The focal blur must be similar somehow to the camera blurring way, not
> conventional AA.  That could be what goes wrong with it I guess, the
camera blur
> method still does an AA on even the sharp focus but the post process seems
to
> remove any AA which was done, or at least cause a backward step.  No doubt
> because that process uses only the 3D info and not the pixel sampling.
That's
> the way I figure it.

True.  Post processed focal blur currently removes some anti-aliasing.  I'm
trying to figure out a way to make it work (without slowing down the render)
but I haven't come up with a good solution.  The problem is that the depth
information for a ray is not anti-aliased, and I don't think that it can be.
I might try, but I just haven't had time recently.

-Nathan

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Warp wrote:

>   Thus, povray's focal blur is physically more accurate.
> 

That's what I thought. I didn't think about the information added to the
image, just plainly that Pov focal blur is calculated along with each
pixel, while the post-procces one does it to the image as a whole,
according to the depth of each pixel (that's how i guess it probably
works). Because of this, Pov takes into account real "out-of-focus"
effects, it doesn't just blur the already-raytraced image.

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TonyB <ben### [at] panamac-comnet> wrote...
> >btw, what's the difference between the post-procces focal blur and the
> >official pov focal blur?
> 
> 
> One is fast, the other is slow. :)
> 

One is physically accurate, the other is totally faked.

-Nathan

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Hey Excuse Me being a newbe and all. But, isn't What was described before
called motion blurring and not focal blur.

In focal blurring no actual information should be added to the scene.
wouldn't that only occur in a side to side or up and down ( or any
combination there of ) motion. Where as true focal blurring only occurs when
the motion is back and forth where the actual focus is changing due to focal
length variation rather than side to side, up and down, or rotational
displacement. ( I get so confused sometimes)

Anyway this doen't make it more accurate does it only that it has more
information to work with in the official POV focal blur and that the
post-process could be just as accurate but it is getting fed less
information to work with.

I don't Know , All I do know is that in reality they are both fake!

Nathan Kopp <Nat### [at] Koppcom> wrote in message
news:38e8c09c@news.povray.org...
>
> TonyB <ben### [at] panamac-comnet> wrote...
> > >btw, what's the difference between the post-procces focal blur and the
> > >official pov focal blur?
> >
> >
> > One is fast, the other is slow. :)
> >
>
> One is physically accurate, the other is totally faked.
>
> -Nathan
>
>

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