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  Focal Blur (Message 1 to 10 of 10)  
From: Josh English
Subject: Focal Blur
Date: 9 Jan 2001 07:42:37
Message: <3A5B0799.14AC8360@spiritone.com>
I have found an anomoly when rendering animations. If I use a camera
that has focal blur, it turns off anti aliasing, but if the next fram
uses a camera without focal blur, anti aliasing does not come back on
for the rest of the animation. Is this a "known bug" that I missed? or
has anyone seen this behaviour before?

--
Josh English -- Lexiphanic Lethomaniac
eng### [at] spiritonecom
The POV-Ray Cyclopedia http://www.spiritone.com/~english/cyclopedia/


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From: Josh English
Subject: Re: Focal Blur
Date: 9 Jan 2001 07:43:14
Message: <3A5B07BE.DE774536@spiritone.com>
Sorry, this is using MegaPov 0.6 on a Mac...

Josh English wrote:

> I have found an anomoly when rendering animations. If I use a camera
> that has focal blur, it turns off anti aliasing, but if the next fram
> uses a camera without focal blur, anti aliasing does not come back on
> for the rest of the animation. Is this a "known bug" that I missed? or
> has anyone seen this behaviour before?
>
> --
> Josh English -- Lexiphanic Lethomaniac
> eng### [at] spiritonecom
> The POV-Ray Cyclopedia http://www.spiritone.com/~english/cyclopedia/

--
Josh English -- Lexiphanic Lethomaniac
eng### [at] spiritonecom
The POV-Ray Cyclopedia http://www.spiritone.com/~english/cyclopedia/


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From: Nicolas Calimet
Subject: Re: Focal Blur
Date: 9 Jan 2001 07:52:58
Message: <3A5B1A02.8BF72B44@free.fr>
Josh English wrote:
> 
> I have found an anomoly when rendering animations. If I use a camera
> that has focal blur, it turns off anti aliasing, but if the next fram
> uses a camera without focal blur, anti aliasing does not come back on
> for the rest of the animation. Is this a "known bug" that I missed? or
> has anyone seen this behaviour before?

	Can't confirm if it's a known bug, but it might be in the
official POV-Ray 3.1g as well. Since the command-line parameters
(or INI settings) are supposed to be parsed only once, and that
focal blur definitely switch off antialiasing by modifying internal
variables, I suspect you can't get the antialiasing back if your
animation does not use it after a while.
	This is just a guess, I'm not sure. But I consider this
behaviour to be inadequate as you mention. Sounds definitely like
a missing feature rather than a bug.


*** Nicolas Calimet
*** http://pov4grasp.free.fr


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From: Thorsten Froehlich
Subject: Re: Focal Blur
Date: 9 Jan 2001 11:13:43
Message: <3a5b38b7$1@news.povray.org>
In article <3A5B0799.14AC8360@spiritone.com> , Josh English 
<eng### [at] spiritonecom>  wrote:

> I have found an anomoly when rendering animations. If I use a camera
> that has focal blur, it turns off anti aliasing, but if the next fram
> uses a camera without focal blur, anti aliasing does not come back on
> for the rest of the animation. Is this a "known bug" that I missed? or
> has anyone seen this behaviour before?

Antialiasing is turned on and off on a render by render basis.  The first
frame with focal blur will turn it off, and then it will stay off.


     Thorsten


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From: Josh English
Subject: Re: Focal Blur
Date: 9 Jan 2001 15:39:48
Message: <3A5B7771.3D394CE8@spiritone.com>
This seems counter intuitive, somehow. I understand that focal blur would
remove the anti-aliasing, but I don't know why it wouldn't come back. Is this
a designed feature or simply one that was never implemented?

Josh

(sorry, I don't intend that to sound rude, but I can't phrase the question
any other way, I certainly dont' mean to be insulting or rude. Please
consider it a failure of my language skills)

Thorsten Froehlich wrote:

> In article <3A5B0799.14AC8360@spiritone.com> , Josh English
> <eng### [at] spiritonecom>  wrote:
>
> > I have found an anomoly when rendering animations. If I use a camera
> > that has focal blur, it turns off anti aliasing, but if the next fram
> > uses a camera without focal blur, anti aliasing does not come back on
> > for the rest of the animation. Is this a "known bug" that I missed? or
> > has anyone seen this behaviour before?
>
> Antialiasing is turned on and off on a render by render basis.  The first
> frame with focal blur will turn it off, and then it will stay off.
>
>      Thorsten

--
Josh English -- Lexiphanic Lethomaniac
eng### [at] spiritonecom
The POV-Ray Cyclopedia http://www.spiritone.com/~english/cyclopedia/


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From: Thorsten Froehlich
Subject: Re: Focal Blur
Date: 9 Jan 2001 19:04:16
Message: <3a5ba700@news.povray.org>
In article <3A5B7771.3D394CE8@spiritone.com> , Josh English 
<eng### [at] spiritonecom>  wrote:

> This seems counter intuitive, somehow. I understand that focal blur would
> remove the anti-aliasing, but I don't know why it wouldn't come back. Is this
> a designed feature or simply one that was never implemented?

No, it is a design issue.  POV-Ray cannot know if focal blur will be enabled
in a later frame as it reparses the scene each time.  However, it cannot
know if antialiasing was on or off once it has been turned off automatically
after focal blur has been used.  Practically using focal blur together with
antialiasing is illegal, so it has to do something.  I agree that the
"something" is not logical, but turing on and off focal blur in different
frames is simply a very rare case, so nobody ever noticed this missing
feature...


     Thorsten


____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org


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From: Peter Popov
Subject: Re: Focal Blur
Date: 10 Jan 2001 10:13:32
Message: <ja8o5t8omoqcko5c7n45lkq05ktrsju4jm@4ax.com>
On Tue, 09 Jan 2001 04:44:09 -0800, Josh English
<eng### [at] spiritonecom> wrote:

>I have found an anomoly when rendering animations. If I use a camera
>that has focal blur, it turns off anti aliasing, but if the next fram
>uses a camera without focal blur, anti aliasing does not come back on
>for the rest of the animation. Is this a "known bug" that I missed? or
>has anyone seen this behaviour before?

It is more of an overlooking on the design stage. I'd rather you
report it as a bug and let the developers have it on their reminder
list :)

Since you are using MegaPOV, have you tried using ini_option after the
camera statement? It *might* just work...


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg


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From: Nicolas Calimet
Subject: Re: Focal Blur
Date: 10 Jan 2001 10:45:15
Message: <3A5C93DC.76B86BCE@free.fr>
> No, it is a design issue.  POV-Ray cannot know if focal blur will be enabled
> in a later frame as it reparses the scene each time. 

	This is something I can't understand. The purpose of reparsing the
scene for each frame is especially to be able to change objects/variables/
parameter between frames. With some #if(clock) condition, it should be
possible to turn on and off focal blur or anything else from frame to frame.

> However, it cannot
> know if antialiasing was on or off once it has been turned off automatically
> after focal blur has been used.

	This could be avoided if focal blur was not reverting specific internal
variables...

> Practically using focal blur together with
> antialiasing is illegal, so it has to do something.

	Again something I don't understand: why "illegal" ? In my patch I
managed to turn antialiasing on with focal blur. Only method 2 is able to
work properly because antialiasing occurs "through" every pixel. It gives
much better results for the sharp zone (in focus), especially if this zone
has an important depth. It also helps somewhat to reduce the grainy effect
for pure colours. Of course render time might be longer. But not *that* much.

> I agree that the
> "something" is not logical, but turing on and off focal blur in different
> frames is simply a very rare case, so nobody ever noticed this missing
> feature...

	But it would speed up a lot to turn focal blur off when the effect
is neglectible. For now, I suppose people manage it by starting a new render,
even if the animation is following the same "scene" (no change in camera
viewpoint for instance).
	Okay, I don't flame the current behaviour. It was just my opinion
of what could be easily implemented ;-)


*** Nicolas Calimet
*** http://pov4grasp.free.fr


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From: Thorsten Froehlich
Subject: Re: Focal Blur
Date: 10 Jan 2001 15:41:48
Message: <3a5cc90c@news.povray.org>
In article <3A5C93DC.76B86BCE@free.fr> , Nicolas Calimet <pov### [at] freefr>
wrote:

>> No, it is a design issue.  POV-Ray cannot know if focal blur will be enabled
>> in a later frame as it reparses the scene each time.
>
>  This is something I can't understand. The purpose of reparsing the
> scene for each frame is especially to be able to change objects/variables/
> parameter between frames. With some #if(clock) condition, it should be
> possible to turn on and off focal blur or anything else from frame to frame.

Antialiasing is a command line option.  You cannot set it in a scene because
it has nothing to do with a scene.

>> However, it cannot
>> know if antialiasing was on or off once it has been turned off automatically
>> after focal blur has been used.
>
>  This could be avoided if focal blur was not reverting specific internal
> variables...

Correct.  A redesign of POV-Ray is necessary to remove all these global
variables - that is what will POV-ray 4.0 will be.

>> Practically using focal blur together with
>> antialiasing is illegal, so it has to do something.
>
>  Again something I don't understand: why "illegal" ?

"Illegal" by specification.  There are still reasons (I hope), but I never
looked into the antialiasing code to say why exactly.

>> I agree that the
>> "something" is not logical, but turing on and off focal blur in different
>> frames is simply a very rare case, so nobody ever noticed this missing
>> feature...
>
>  But it would speed up a lot to turn focal blur off when the effect
> is neglectible. For now, I suppose people manage it by starting a new render,
> even if the animation is following the same "scene" (no change in camera
> viewpoint for instance).

Well, the whole problem is based on the ten year development.  You don't
have the same problem with POV-Ray 2.2 because it does not support an
internal render loop.  You can still revert to this behaviour in 3.1 by only
setting the clock and render individual frames, as you suggested.

>  Okay, I don't flame the current behaviour. It was just my opinion
> of what could be easily implemented ;-)

Understood, but keep in mind that something that sounds easy may not always
be as easy as you think at first sight...


    Thorsten


____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org


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From: Josh English
Subject: Re: Focal Blur
Date: 11 Jan 2001 07:54:44
Message: <3A5DAD7E.AC243EA2@spiritone.com>
I haven't tried that, since I am a strange hybrid user. I use MegaPov
because it seems to parse and render faster, but I try (for some ineffable
reason) to make scenes that are 3.1 compliant. Thanks for the tip, though.
I will implement it

Josh

Peter Popov wrote:

> On Tue, 09 Jan 2001 04:44:09 -0800, Josh English
> <eng### [at] spiritonecom> wrote:
>
> >I have found an anomoly when rendering animations. If I use a camera
> >that has focal blur, it turns off anti aliasing, but if the next fram
> >uses a camera without focal blur, anti aliasing does not come back on
> >for the rest of the animation. Is this a "known bug" that I missed? or
> >has anyone seen this behaviour before?
>
> It is more of an overlooking on the design stage. I'd rather you
> report it as a bug and let the developers have it on their reminder
> list :)
>
> Since you are using MegaPOV, have you tried using ini_option after the
> camera statement? It *might* just work...
>
> Peter Popov ICQ : 15002700
> Personal e-mail : pet### [at] vipbg
> TAG      e-mail : pet### [at] tagpovrayorg

--
Josh English -- Lexiphanic Lethomaniac
eng### [at] spiritonecom
The POV-Ray Cyclopedia http://www.spiritone.com/~english/cyclopedia/


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