Nieminen Juha <war### [at] sarakerttunencstutfi> wrote...
>   A more general approach:
>   Add a new keyword, eg. 'no_antialiasing'. When applied to an object,
then
> a ray hitting this object will stop the supersampling immediately. Should
> be easy to implement.

This could end up more complicated than you might think.

First, radiosity sampling methods generally re-use points from one pixel
calculation to the next.  This would probably not be a problem, though (I
think POV implements something like a dirty-pixel buffer that determines if
it needs to trace the sample or not).

Second, what do you do if you can see an object _through_ another object.
What if the clear blocking object is a crystal?  What if it is, instead, a
media container object?  I have been wondering how to handle this and
similar questions when dealing with post-processing.  There will be ways to
tag objects for post processing, and then let the filter find out if a
tagged object was hit.  But how should those clear media containers be
handled???  And what about not-so-perfectly-clear, yet mostly clear,
objects, like a wine glass.  The other thing to worry about for me is depth.
Which depth should be returned: the first object hit, or the first object
that you'd actually _see_?

-Nathan

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On Wed, 16 Feb 2000 00:42:37 +0100, Paul Blaszczyk <3d### [at] alpharayde>
wrote:

>In my opinion, two VERY USEFUL features:
>
>- no anti-alias against background
>    -> to render sprites, buttons, etc.

Render your scene. Save the image.

Add these options to the command line:

+q0 +ua -d -a

Render and save again. Now use the alpha channel from the second image
with the first image and you have an anti-aliased sprite.


Peter Popov
pet### [at] tagpovrayorg
ICQ: 15002700

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Nathan Kopp <Nat### [at] koppcom> wrote:
: Second, what do you do if you can see an object _through_ another object.

  Well, I think that it could be implemented anyways. The documentation could
state that "this feature may not work well with transparent objects" or
something like that.
  After all, this feature will likely to be used in situations where the
non-antialiased object is directly seen from the camera (like sky spheres
with granite pigment simulating a starfield, etc).
  And if media is not antialiased (because there's a starry sky behind it),
does it matter? AFAIK media doesn't need antialiasing.

-- 
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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In article <38abca64@news.povray.org>, Nieminen Juha 
<war### [at] sarakerttunencstutfi> wrote:

> Nathan Kopp <Nat### [at] koppcom> wrote:
> : Second, what do you do if you can see an object _through_ another 
> : object.
> 
>   Well, I think that it could be implemented anyways. The documentation 
>   could
> state that "this feature may not work well with transparent objects" or
> something like that.
>   After all, this feature will likely to be used in situations where the
> non-antialiased object is directly seen from the camera (like sky spheres
> with granite pigment simulating a starfield, etc).
>   And if media is not antialiased (because there's a starry sky behind 
>   it),
> does it matter? AFAIK media doesn't need antialiasing.


One solution would be to trace one ray, if it hits an object, check that 
object for a flag that tells whether or not to supersample it, and fire 
additional samples based on that information. This would be done at each 
level. It should work correctly with transparency and media, although it 
should probably be turned off when "global" anti-aliasing is turned on.

-- 
Chris Huff
e-mail: chr### [at] yahoocom
Web page: http://chrishuff.dhs.org/

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Peter Popov schrieb:

> On Wed, 16 Feb 2000 00:42:37 +0100, Paul Blaszczyk <3d### [at] alpharayde>
> wrote:
>
> >In my opinion, two VERY USEFUL features:
> >
> >- no anti-alias against background
> >    -> to render sprites, buttons, etc.
>
> Render your scene. Save the image.
>
> Add these options to the command line:
>
> +q0 +ua -d -a
>
> Render and save again. Now use the alpha channel from the second image
> with the first image and you have an anti-aliased sprite.

Good idea...for one button or sprite. But what is with animated sprites
(with MUCH frames)? (e.g. for a game... 100 frames per figure and 10
figures in game).

Paul

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<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
 
<p>Chris Huff schrieb:
<blockquote TYPE=CITE>In article <38aa7e1b@news.povray.org>, Nieminen
Juha
<br><war### [at] sarakerttunencstutfi> wrote:
<p>> : - reflection-map
<br>> :     -> the current reflections are to perfect.
Current scenes seems
<br>> :     much
<br>> : to clean!
<br>>
<br>>   Wouldn't blurred reflection just do it?
<p>I believe what he wants is a way to vary the amount of reflection
<br>according to a pattern without having to use a texture_map</blockquote>
Right   :-)
<br> 
<blockquote TYPE=CITE>. A finish_map should be sufficient for this,
though...</blockquote>
Thats better...because a less-reflective part is "dirtier" and have a bigger
and darker highlight (in POV:  a smaller brilliance, phong- and phong_size
value).
<br>With a finish_map is would be also possible to create dirtier scenes
(e.g. different ambient/diffuse values to simulate worse painted walls...a
splotchy-effect).
<p>  Paul</html>

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On Thu, 17 Feb 2000 13:16:18 +0100, Paul Blaszczyk wrote:
>Good idea...for one button or sprite. But what is with animated sprites
>(with MUCH frames)? (e.g. for a game... 100 frames per figure and 10
>figures in game).

Automate the process with a batch file or shell script.  Using the alpha
channel from one image with the other can probably be done with the GIMP's
or Photoshop's automation features.

-- 
These are my opinions.  I do NOT speak for the POV-Team.
The superpatch: http://www2.fwi.com/~parkerr/superpatch/
My other stuff: http://www2.fwi.com/~parkerr/traces.html

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On Thu, 17 Feb 2000 05:49:23 -0500, Chris Huff wrote:
>One solution would be to trace one ray, if it hits an object, check that 
>object for a flag that tells whether or not to supersample it, and fire 
>additional samples based on that information. This would be done at each 
>level. It should work correctly with transparency and media, although it 
>should probably be turned off when "global" anti-aliasing is turned on.

Another solution (at least for method 1 antialiasing) would be to use the
differential tracing method I've mentioned far too many times before.  I
think I may sit down sometime in the next couple of weeks and see how hard
it is to implement that.

-- 
These are my opinions.  I do NOT speak for the POV-Team.
The superpatch: http://www2.fwi.com/~parkerr/superpatch/
My other stuff: http://www2.fwi.com/~parkerr/traces.html

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On 17 Feb 2000 08:35:08 -0500, ron### [at] povrayorg (Ron Parker)
wrote:

>On Thu, 17 Feb 2000 13:16:18 +0100, Paul Blaszczyk wrote:
>>Good idea...for one button or sprite. But what is with animated sprites
>>(with MUCH frames)? (e.g. for a game... 100 frames per figure and 10
>>figures in game).
>
>Automate the process with a batch file or shell script.  Using the alpha
>channel from one image with the other can probably be done with the GIMP's
>or Photoshop's automation features.

Instead of using the alpha channel, you can give all objects a
quick_color rgb 1 and render with +q0. Then you can use this image as
a image_patterm with no interpolation. There you are, all you need is
POV.

All you need is POV (ta tada tadaaa)
All you need is POV (ta tada tadaaa)
All you need is POV, POV,
POV is all you need

:)


Peter Popov
pet### [at] tagpovrayorg
ICQ: 15002700

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Peter Popov wrote:

> All you need is POV (ta tada tadaaa)
> All you need is POV (ta tada tadaaa)
> All you need is POV, POV,
> POV is all you need

For some reason I suddenly feel like stepping on a beetle.

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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