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From: Mike Horvath
Subject: Blurred reflection comparison
Date: 12 Feb 2018 08:08:55
Message: <5a8191e7$1@news.povray.org>
I still don't understand how I'm supposed to achieve the blurred 
reflections possible in UberPOV by just using a little focal blur. 
Compare the two attached images - especially the reflections in the 
circled parts.


Mike


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Attachments:
Download 'building_007_firecompany_reflection_01.jpg' (197 KB) Download 'building_007_firecompany_reflection_02.jpg' (200 KB)

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building_007_firecompany_reflection_01.jpg

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building_007_firecompany_reflection_02.jpg


 

From: clipka
Subject: Re: Blurred reflection comparison
Date: 12 Feb 2018 13:21:30
Message: <5a81db2a@news.povray.org>
Am 12.02.2018 um 14:08 schrieb Mike Horvath:
> I still don't understand how I'm supposed to achieve the blurred
> reflections possible in UberPOV by just using a little focal blur.
> Compare the two attached images - especially the reflections in the
> circled parts.

Focal blur is just part of the equation.

You need:

(1) A way to randomize the reflection. A `normal` statement with a very
small scale does nicely.

(2) A way to force POV-Ray to shoot a high number of rays per pixel
where the randomized reflection is. A small bit of focal blur (with high
quality settings) does nicely.

Together this gives you nice blurred reflections at a (hopefully)
reasonable speed.


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From: Mike Horvath
Subject: Re: Blurred reflection comparison
Date: 12 Feb 2018 16:27:14
Message: <5a8206b2$1@news.povray.org>
On 2/12/2018 1:21 PM, clipka wrote:
> Am 12.02.2018 um 14:08 schrieb Mike Horvath:
>> I still don't understand how I'm supposed to achieve the blurred
>> reflections possible in UberPOV by just using a little focal blur.
>> Compare the two attached images - especially the reflections in the
>> circled parts.
> 
> Focal blur is just part of the equation.
> 
> You need:
> 
> (1) A way to randomize the reflection. A `normal` statement with a very
> small scale does nicely.
> 
> (2) A way to force POV-Ray to shoot a high number of rays per pixel
> where the randomized reflection is. A small bit of focal blur (with high
> quality settings) does nicely.
> 
> Together this gives you nice blurred reflections at a (hopefully)
> reasonable speed.
> 

Is this random normal good?




#declare BlurAmount = 0.2*2; // Amount of blurring, double BlurAmount 
since it's used in an average
#macro BlurredReflectionRandNormals(InPigment, InFinish, InNormal)
//	texture
//	{
		#declare S = seed(0);
		pigment { InPigment }
		finish { InFinish }
		normal
		{
			average
			normal_map
			{
				[1 bumps BlurAmount translate <rand(S),rand(S),rand(S)>*100 scale 0.001]
				[1 InNormal]
			}
		}
//	}
#end


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From: clipka
Subject: Re: Blurred reflection comparison
Date: 12 Feb 2018 17:05:51
Message: <5a820fbf$1@news.povray.org>
Am 12.02.2018 um 22:27 schrieb Mike Horvath:

>> You need:
>>
>> (1) A way to randomize the reflection. A `normal` statement with a very
>> small scale does nicely.
>>
>> (2) A way to force POV-Ray to shoot a high number of rays per pixel
>> where the randomized reflection is. A small bit of focal blur (with high
>> quality settings) does nicely.
>>
>> Together this gives you nice blurred reflections at a (hopefully)
>> reasonable speed.
>>
> 
> Is this random normal good?

It should do the job. Note that since you're only using one copy of the
bumps normal, there's no need to translate the texture by a random amount.

Also, I'm not sure whether the average normal_map construct will give
you the desired result, or whether you should instead use a sequence of
`normal` statements. See tutorial section 2.3.5.2.2, "Blending Normals".


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From: Mike Horvath
Subject: Re: Blurred reflection comparison
Date: 12 Feb 2018 22:11:42
Message: <5a82576e@news.povray.org>
On 2/12/2018 5:05 PM, clipka wrote:
> Am 12.02.2018 um 22:27 schrieb Mike Horvath:
> 
>>> You need:
>>>
>>> (1) A way to randomize the reflection. A `normal` statement with a very
>>> small scale does nicely.
>>>
>>> (2) A way to force POV-Ray to shoot a high number of rays per pixel
>>> where the randomized reflection is. A small bit of focal blur (with high
>>> quality settings) does nicely.
>>>
>>> Together this gives you nice blurred reflections at a (hopefully)
>>> reasonable speed.
>>>
>>
>> Is this random normal good?
> 
> It should do the job. Note that since you're only using one copy of the
> bumps normal, there's no need to translate the texture by a random amount.
> 
> Also, I'm not sure whether the average normal_map construct will give
> you the desired result, or whether you should instead use a sequence of
> `normal` statements. See tutorial section 2.3.5.2.2, "Blending Normals".
> 

Very nice, thank you.


Mike


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From: Mike Horvath
Subject: Re: Blurred reflection comparison
Date: 13 Feb 2018 00:12:43
Message: <5a8273cb$1@news.povray.org>
On 2/12/2018 5:05 PM, clipka wrote:
> Am 12.02.2018 um 22:27 schrieb Mike Horvath:
> 
>>> You need:
>>>
>>> (1) A way to randomize the reflection. A `normal` statement with a very
>>> small scale does nicely.
>>>
>>> (2) A way to force POV-Ray to shoot a high number of rays per pixel
>>> where the randomized reflection is. A small bit of focal blur (with high
>>> quality settings) does nicely.
>>>
>>> Together this gives you nice blurred reflections at a (hopefully)
>>> reasonable speed.
>>>
>>
>> Is this random normal good?
> 
> It should do the job. Note that since you're only using one copy of the
> bumps normal, there's no need to translate the texture by a random amount.
> 
> Also, I'm not sure whether the average normal_map construct will give
> you the desired result, or whether you should instead use a sequence of
> `normal` statements. See tutorial section 2.3.5.2.2, "Blending Normals".
> 

How do I control the amount of blurring? In my scene the textures are 
maybe a little too blurred.


Mike


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From: clipka
Subject: Re: Blurred reflection comparison
Date: 13 Feb 2018 01:56:22
Message: <5a828c16$1@news.povray.org>
Am 13.02.2018 um 06:12 schrieb Mike Horvath:

> How do I control the amount of blurring? In my scene the textures are
> maybe a little too blurred.

Reducing `BlurAmount` in your code should reduce the blurriness of the
reflections.

Reducing the camera's `aperture` setting should reduce any overall
blurriness of the image.


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From: Alain
Subject: Re: Blurred reflection comparison
Date: 13 Feb 2018 19:31:28
Message: <5a838360$1@news.povray.org>
Le 18-02-12 à 16:27, Mike Horvath a écrit :
> On 2/12/2018 1:21 PM, clipka wrote:
>> Am 12.02.2018 um 14:08 schrieb Mike Horvath:
>>> I still don't understand how I'm supposed to achieve the blurred
>>> reflections possible in UberPOV by just using a little focal blur.
>>> Compare the two attached images - especially the reflections in the
>>> circled parts.
>>
>> Focal blur is just part of the equation.
>>
>> You need:
>>
>> (1) A way to randomize the reflection. A `normal` statement with a very
>> small scale does nicely.
>>
>> (2) A way to force POV-Ray to shoot a high number of rays per pixel
>> where the randomized reflection is. A small bit of focal blur (with high
>> quality settings) does nicely.
>>
>> Together this gives you nice blurred reflections at a (hopefully)
>> reasonable speed.
>>
> 
> Is this random normal good?
> 
> 
> 
> 
> #declare BlurAmount = 0.2*2; // Amount of blurring, double BlurAmount 
> since it's used in an average
> #macro BlurredReflectionRandNormals(InPigment, InFinish, InNormal)
> //    texture
> //    {
>          #declare S = seed(0);
>          pigment { InPigment }
>          finish { InFinish }
>          normal
>          {
>              average
>              normal_map
>              {
>                  [1 bumps BlurAmount translate 
> <rand(S),rand(S),rand(S)>*100 scale 0.001]
>                  [1 InNormal]
>              }
>          }
> //    }
> #end

It's good in the sense that it will not cause any error.
BUT.. At parse time, it will compute the average between the two normals 
into a single one that will get used. This result in only a single 
reflected ray been taken into count.
I did try averaging many normals and it always give a sharp reflection.

To use the averaged normals blurred reflection, you need to average 
whole textures.

Move the seed before the average.
Enclose the texture in a loop construct.
Place that loop within your average.


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From: Mike Horvath
Subject: Re: Blurred reflection comparison
Date: 13 Feb 2018 23:50:38
Message: <5a83c01e$1@news.povray.org>
On 2/13/2018 1:56 AM, clipka wrote:
> Am 13.02.2018 um 06:12 schrieb Mike Horvath:
> 
>> How do I control the amount of blurring? In my scene the textures are
>> maybe a little too blurred.
> 
> Reducing `BlurAmount` in your code should reduce the blurriness of the
> reflections.
> 
> Reducing the camera's `aperture` setting should reduce any overall
> blurriness of the image.
> 

This is my latest macro. I used a sequential list of normals instead of 
averaging them. It looks okay.

Mike





// this method is faster, but requires a focal blur and/or extra 
antialiasing
#declare BlurAmount = 0.1;
#macro BlurredReflectionRegularNormals(InPigment, InFinish, InNormal)
//	texture
//	{
		pigment { InPigment }
		finish { InFinish }
		normal { InNormal }
		normal {bumps BlurAmount scale 0.001}
//	}
#end


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From: Mike Horvath
Subject: Re: Blurred reflection comparison
Date: 15 Feb 2018 14:26:15
Message: <5a85ded7@news.povray.org>
Here's my latest town render. You can see the pixelation in the 
reflections. I haven't been able to get rid of it using more focal blur 
and anti-aliasing. I will keep trying.


Mike


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Download 'wrapper_townview_10.jpg' (1057 KB)

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