POV-Ray : Newsgroups : povray.beta-test.binaries : Playpen idea for povr -1 to 1 seed patterns. Server Time
23 Apr 2024 13:56:21 EDT (-0400)
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From: William F Pokorny
Subject: Playpen idea for povr -1 to 1 seed patterns.
Date: 11 Oct 2020 14:14:51
Message: <5f834b9b@news.povray.org>
While thinking of deleting the quilted value pattern, started to toy 
with the idea of replacing it with a seed pattern having values in the 
function_interval range of -1 to 1.

The wave shape modifiers have been extended to support +- function 
values, but to make use of them without some seed, you need to create 
functions as input.

What if we had one or more seed or base patterns aimed at being fuel for 
more complex patterns?

Idea thus far looks promising.Two images attached. One showing the 
concept from seed pattern through to more complex patterns derived from 
it. The other a larger fall color image using the technique.

A - The seed pattern on a y plane. Negative values as red and positive 
values as green. The black between the near 0 values.(using 
function_interval)

B - What is in A, but used directly in an isosurface.

C - Combining two of A in an average pigment. (function_interval)

D - Pattern of C as an isosurface.

E - C pattern (adding sine_wave along with function_interval)

F - Using E in an isosurface.

G - Adding six more rotations of A to the C average pigment.

H - G using the modified povr cubic_wave (selection) functionality.

I - H adding phase -0.1 to shift the colors toward negative red.

J - H again with phase +0.1 and adding some turbulence.

K - J adding the povr wave inverse wave keyword.

L - J made more turbulent. Adding a light to the scene.

Bill P.


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Attachments:
Download 'seedpattrnstory.jpg' (438 KB) Download 'fallcolors.jpg' (285 KB)

Preview of image 'seedpattrnstory.jpg'
seedpattrnstory.jpg

Preview of image 'fallcolors.jpg'
fallcolors.jpg


 

From: William F Pokorny
Subject: Re: Playpen idea for povr -1 to 1 seed patterns.
Date: 12 Oct 2020 07:25:38
Message: <5f843d32@news.povray.org>
On 10/11/20 2:14 PM, William F Pokorny wrote:
> While thinking of deleting the quilted value pattern, started to toy 
> with the idea of replacing it with a seed pattern having values in the 
> function_interval range of -1 to 1.
> 
...
> 
> J - H again with phase +0.1 and adding some turbulence.
> 
> K - J adding the povr wave inverse wave keyword.
> 
> L - J made more turbulent. Adding a light to the scene.
> 

One more isosurface image using something similar to L to displace a 
surface.

It reminds me a little of a tunnel I once traversed. A tunnel created by 
blasting through solid rock.

Bill P.


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Attachments:
Download 'hmmhmm.jpg' (295 KB)

Preview of image 'hmmhmm.jpg'
hmmhmm.jpg


 

From: William F Pokorny
Subject: Re: Playpen idea for povr -1 to 1 seed patterns.
Date: 12 Oct 2020 10:15:11
Message: <5f8464ef$1@news.povray.org>
On 10/11/20 2:14 PM, William F Pokorny wrote:
> While thinking of deleting the quilted value pattern, started to toy 
> with the idea of replacing it with a seed pattern having values in the 
> function_interval range of -1 to 1.
> 
...

One more. I had thought I could create another image where I scale the 
seed derived pattern very small creating a really good stress tests for 
the am3 anti-alias mode.

Since that set of cases am1,am2,am3 cases making sure there was no 
overall color shift, I've been carrying this a the am3 mode really worth 
much over heavy am1/am2.

It's valuable here. Fed the input on the left (no AA) - there is  much 
more 'line-ish' detail below what is seen. The am3 mode came out quite a 
bit faster than am2 for equivalent threshold and depth. The fixed am3 
and confidence set at 0.98. Resulting images not identical, but very close.

3 minutes 56 seconds (236.791 seconds)   am3
Pixels: 490000 Samples: 425852553 Smpls/Pxl: 869.09

5 minutes 30 seconds (330.180 seconds)   am2
Pixels: 521284 Samples: 531634923 Smpls/Pxl: 1019.86

869.09 -> 1019.9 ---> 17.35%
236.8s -> 330.2s ---> 39.44%

Bill P.


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Attachments:
Download 'am2vsam3.jpg' (131 KB)

Preview of image 'am2vsam3.jpg'
am2vsam3.jpg


 

From: William F Pokorny
Subject: Re: Playpen idea for povr -1 to 1 seed patterns.
Date: 13 Oct 2020 04:13:51
Message: <5f8561bf$1@news.povray.org>
On 10/12/20 10:15 AM, William F Pokorny wrote:
> I've been carrying this a the am3 mode really worth much over heavy am1/am2.

Argh... Should have read something like:

"I've been carrying this doubt whether the am3 mode really worth much 
over heavy am1/am2."

With the example posted, it's the best choice.

Bill P.


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From: William F Pokorny
Subject: Re: Playpen idea for povr -1 to 1 seed patterns.
Date: 14 Oct 2020 15:05:41
Message: <5f874c05$1@news.povray.org>
On 10/13/20 4:13 AM, William F Pokorny wrote:
> On 10/12/20 10:15 AM, William F Pokorny wrote:
...
> 
> With the example posted, it's the best choice.
> 

And should add another very good reason to keep - and use - aa method 3 
is the stochastic seed capability. This lets us get a repeatable aa 
method 1, 2 type result without the randomness of the jitter in methods 
one and two.

Bill P.


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From: Kenneth
Subject: Re: Playpen idea for povr -1 to 1 seed patterns.
Date: 19 Oct 2020 09:20:07
Message: <web.5f8d91847d75f86cd98418910@news.povray.org>
William F Pokorny <ano### [at] anonymousorg> wrote:

> It's valuable here. Fed the input on the left (no AA) - there is  much
> more 'line-ish' detail below what is seen. The am3 mode came out quite a
> bit faster than am2 for equivalent threshold and depth. The fixed am3
> and confidence set at 0.98. Resulting images not identical, but very close.
>
> With the example posted, it's the best choice.

So just to be clear: The image on the left is with NO AA, and the image on the
right is with the stochastic am3 method? That looks really good.
>
>
> And should add another very good reason to keep - and use - aa method 3
> is the stochastic seed capability. This lets us get a repeatable aa
> method 1, 2 type result without the randomness of the jitter in methods
> one and two.
>

So it seems to be the best thing to use for AA in animations... although there
are two notes in the documentation:
"Conversely you can produce exactly the same output each time. See also:
Stochastic Seed."

That sounds good. But...
"Note: The jitter sequence is also affected by the actual image content, and
will thus always differ between the frames of an animation."

If I understand this correctly, it makes me wonder if there *would* be a
visually noticiable jittering when using the am3 method. I guess I need to try
it, to see.

Thanks for these tests.


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From: William F Pokorny
Subject: Re: Playpen idea for povr -1 to 1 seed patterns.
Date: 19 Oct 2020 09:55:02
Message: <5f8d9ab6$1@news.povray.org>
On 10/19/20 9:15 AM, Kenneth wrote:
> William F Pokorny <ano### [at] anonymousorg> wrote:
> 
> If I understand this correctly, it makes me wonder if there *would* be a
> visually noticiable jittering when using the am3 method. I guess I need to try
> it, to see.
> 
Good

Good question! I don't believe jitter is used in am3, but I did not test 
that belief. Let us know what you find.

Bill P.


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From: Kenneth
Subject: Re: Playpen idea for povr -1 to 1 seed patterns.
Date: 19 Oct 2020 17:30:00
Message: <web.5f8e045f7d75f86cd98418910@news.povray.org>
William F Pokorny <ano### [at] anonymousorg> wrote:
> On 10/19/20 9:15 AM, Kenneth wrote:
> > William F Pokorny <ano### [at] anonymousorg> wrote:
> >
> > If I understand this correctly, it makes me wonder if there *would* be a
> > visually noticiable jittering when using the am3 method. I guess I need to try
> > it, to see.
> >
>
> Good question! I don't believe jitter is used in am3, but I did not test
> that belief. Let us know what you find.
>

I just tried to test it, but it's throwing an error.

I'm running the latest v3.8 development build in Windows, but it does not accept
the   Antialias_Confidence=  keyword in my quickres.ini file(!)

[1280x960, AA special]
Width=1280
Height=960
Antialias=On
Sampling_Method=3
Antialias_Confidence=0.98  <------- not accepted
Antialias_Threshold=0.05

I tried instead to use +AC0.98 on the command line, but it does not work there
either. I don't know what I'm doing wrong. Help!


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From: Kenneth
Subject: Re: Playpen idea for povr -1 to 1 seed patterns.
Date: 19 Oct 2020 17:55:00
Message: <web.5f8e09b27d75f86cd98418910@news.povray.org>
"Kenneth" <kdw### [at] gmailcom> wrote:
>
> I just tried to test it, but it's throwing an error.
>
> I'm running the latest v3.8 development build in Windows, but it does not accept
> the   Antialias_Confidence=  keyword in my quickres.ini file(!)
> ...
> I tried instead to use +AC0.98 on the command line, but it does not work there
> either. I don't know what I'm doing wrong. Help!

I forgot to mention that Stochastic_Seed (or +SS) is not accepted either, in
either location.

It seems that v3.8 in Windows is not recognizing those terms. :-(  If I leave
them out completely, I AM able to render-- but without the Stochastic_Seed
mechanism, I can't do a 'thorough' animation test for possible jitter.


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From: Kenneth
Subject: Re: Playpen idea for povr -1 to 1 seed patterns.
Date: 19 Oct 2020 18:30:00
Message: <web.5f8e13487d75f86cd98418910@news.povray.org>
"Kenneth" <kdw### [at] gmailcom> wrote:

>
> I forgot to mention that Stochastic_Seed (or +SS) is not accepted either, in
> either location.
>
> It seems that v3.8 in Windows is not recognizing those terms. :-(

I did an animation test anyway, by simply leaving out the two terms.

my .ini file:
[1280x960, AA special]
Width=1280
Height=960
Antialias=On
Sampling_Method=3
Antialias_Threshold=0.05

Nothing moves in my scene, or the camera; just static animation frames. I took
two consecutive frames into Photoshop, 'differenced' them, and exaggerated any
possible defects. And I don't see ANY difference between the two images-- no
out-of-place pixles at all. :-) Perhaps Stochastic_Seed is already 'on' by
default in the Windows version(?). In any case, the renders are beautifully
antialiased, and consistent.

Perhaps a *moving* camera might show something-- but any am3 difference from
frame to frame would be hard to verify by itself, since everything else is
slightly changing as well.


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