POV-Ray : Newsgroups : povray.binaries.images : 2020 year in review Server Time
29 Mar 2024 01:35:41 EDT (-0400)
  2020 year in review (Message 11 to 14 of 14)  
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From: Alain Martel
Subject: Re: 2020 year in review
Date: 6 Jan 2021 12:44:44
Message: <5ff5f70c$1@news.povray.org>

> Alain Martel <kua### [at] videotronca> wrote:
> 
>>
>> I tend to use some averaged micro-normals. Around 5 to 10 seems to work
>> well.
>> I prefer to use granite as my base pattern.
>> I also use rather large random translations after the scaling.
> 
> Granite-- I never thought of that. It is nicely 'random'. My own trials used
> overlapped and rotated 'linear' patterns... like sine waves or scallop waves for
> the normals, IIRC. Maybe that was the cause of my Moire patterns? I need to
> experiment with your method.
> 
> 

You can also try bozo/bumps/spotted or agate as your base pattern.
You can mix different patterns.

For example, you can use a large scale bozo and overlay it with 
micro-normals using granite.

There are so many possibilities, you need to explore.

Tip when using averaged textures for complex objects or multiple objects 
with blurred reflection :

Make two copies of your objects with blurred reflection. The first have 
the full averaged texture and the no_reflection attribute. The second 
have only the non-averaged micro-normals and the no_image attribute.
That way, when that object self reflect, or several objects that have 
blurred reflection inter reflect, the number of rays to trace is kept to 
a reasonable level.
This is not useful in the present case as the only surface with blurred 
reflection is a ground plane.

Also, using averaged textures can be much faster that rendering multiple 
times and averaging the resulting images externally. The render time hit 
only affect the part of the image where there are averaged normals. 
Multiple renders need to render the whole image multiple times, then, 
you have the time needed to post process them.


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From: Cousin Ricky
Subject: Re: 2020 year in review
Date: 7 Jan 2021 22:45:55
Message: <5ff7d573$1@news.povray.org>
On 2021-01-06 1:44 PM (-4), Alain Martel wrote:

>> Alain Martel <kua### [at] videotronca> wrote:
>>
>>> I tend to use some averaged micro-normals. Around 5 to 10 seems to work
>>> well.
>>> I prefer to use granite as my base pattern.
>>> I also use rather large random translations after the scaling.
>>
>> Granite-- I never thought of that. It is nicely 'random'. My own 
>> trials used
>> overlapped and rotated 'linear' patterns... like sine waves or scallop 
>> waves for
>> the normals, IIRC. Maybe that was the cause of my Moire patterns?

I suspect so.  Think of the regular patterns you see in 4-color 
halftones in comic books.

However, Rune Johansen has a brushed metal texture that just averages 2 
wood layers.  It is quite convincing, even with no blur effect.  It was 
written for MegaPOV 0.5, but it is easily converted to 3.7/3.8.
   http://runevision.com/3d/povgoodies/

> You can also try bozo/bumps/spotted or agate as your base pattern.

I tried crackle once, but it took longer than bumps and didn't look all 
that great.  Facets coords gives results similar to bumps, without 
taking longer.

I have never thought to try granite or agate.  Have you tried wrinkles?

> Tip when using averaged textures for complex objects or multiple objects 
> with blurred reflection :
> 
> Make two copies of your objects with blurred reflection. The first have 
> the full averaged texture and the no_reflection attribute. The second 
> have only the non-averaged micro-normals and the no_image attribute.
> That way, when that object self reflect, or several objects that have 
> blurred reflection inter reflect, the number of rays to trace is kept to 
> a reasonable level.

My RC3Metal module in the Object Collection uses this trick.  Thanks 
again for that idea.

> Also, using averaged textures can be much faster that rendering multiple 
> times and averaging the resulting images externally. The render time hit 
> only affect the part of the image where there are averaged normals. 
> Multiple renders need to render the whole image multiple times, then, 
> you have the time needed to post process them.

This was my first plan.  But I had written the original scene using 
POV-Ray 3.7, so to get the same effect as finish-level Fresnel, I had 
used a layered texture.  (Trust me, reflection-level Fresnel looked 
horrible.)  Then when I tried to change the bumpy layer to an averaged 
texture, I got the old "Cannot layer a patterned texture over another" 
error.  Rather than attempt to rearrange the texture, or unravel the 
texture to work with 3.8's finish-level Fresnel, I just chose the easy 
way out.  But yes, I agree that putting in the extra work would probably 
have shortened the render time.


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From: Kenneth
Subject: Re: 2020 year in review
Date: 8 Jan 2021 12:30:01
Message: <web.5ff895dec28df99d98418910@news.povray.org>
Alain Martel <kua### [at] videotronca> wrote:
>
> Tips when using averaged textures for complex objects or multiple objects
> with blurred reflection...

Some very good tips; thanks Alain.

Cousin Ricky wrote:
> Rune Johansen has a brushed metal texture that just averages 2
> wood layers.  It is quite convincing, even with no blur effect.  It was
> written for MegaPOV 0.5, but it is easily converted to 3.7/3.8.
>    http://runevision.com/3d/povgoodies/

Ah yes, thanks. I had lost that link. (I think it was my initial 'introduction'
to blurred reflections and such.)


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From: Jörg "Yadgar" Bleimann
Subject: Re: 2020 year in review
Date: 11 Jan 2021 06:34:05
Message: <5ffc37ad$1@news.povray.org>
Hi(gh)!

On 05.01.21 16:17, Alain Martel wrote:

> D. Trump is probably the worst leader to ever lead any country in Human 
> History. And, yes, he's bat shit crazy.

I disagree - far from being a Trumpist, I would say that Hitler, Stalin, 
Pol Pot and Mao Tse-Tung were far worse! At least as long as Trump 
doesn't declare a full-scale nuclear war on Russia and China just hours 
before his tenure ends, just to ultimately demonstrate his psychopathy...

See you in Khyberspace!

Yadgar

Now playing: Little Neutrino (Klaatu)


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