POV-Ray : Newsgroups : povray.binaries.images : A radial pattern contains randomize(bump) Server Time22 Sep 2023 14:13:23 EDT (-0400)
 A radial pattern contains randomize(bump) (Message 1 to 10 of 15)
 From: And Subject: A radial pattern contains randomize(bump) Date: 26 Aug 2023 05:15:00 Message:
```
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"dateCreated": "2023-08-26T09:15:00+00:00",
"datePublished": "2023-08-26T09:15:00+00:00",
"author": {
"@type": "Person",
"name": "And"
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I suddenly solve an important problem. About how to generate a circle associated
pattern.

I need such a pattern for my wood-pattern generator.
For wood heart, I don't have good function in the past. But these series opens a
window.
```

Attachments:

Preview of image 'radial associate function.png'

 From: And Subject: Re: A radial pattern contains randomize(bump) Date: 26 Aug 2023 05:20:00 Message:
```
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"dateCreated": "2023-08-26T09:20:00+00:00",
"datePublished": "2023-08-26T09:20:00+00:00",
"author": {
"@type": "Person",
"name": "And"
}
}
Another one. This one superposition two such a bump.
```

Attachments:

Preview of image 'radial composite function.png'

 From: And Subject: Re: A radial pattern contains randomize(bump) Date: 26 Aug 2023 05:30:00 Message:
```
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"@type": "DiscussionForumPosting",
"@id": "#web.64e9c4ec24fd44d93a0d3e9baa81652d%40news.povray.org",
"dateCreated": "2023-08-26T09:30:00+00:00",
"datePublished": "2023-08-26T09:30:00+00:00",
"author": {
"@type": "Person",
"name": "And"
}
}
Another one.
In fact I'm not very understand why these function expression generate such
pattern.

Of course I should try to use 2, 3, 4, ... maybe 6~7 bumps superposition.
```

Attachments:

Preview of image 'radial bump function record3.png'

 From: And Subject: Re: A radial pattern contains randomize(bump) Date: 26 Aug 2023 05:35:00 Message:
```
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"@type": "DiscussionForumPosting",
"@id": "#web.64e9c73524fd44d93a0d3e9baa81652d%40news.povray.org",
"dateCreated": "2023-08-26T09:35:00+00:00",
"datePublished": "2023-08-26T09:35:00+00:00",
"author": {
"@type": "Person",
"name": "And"
}
}
Another situation is ... looks like near degradation.

Using more large number for coefficient of f_external_field.

#declare f_external_field =
function(x, y) {
2.0*sqrt(x*x + y*y) + 0.2
//^^^
}

This one using 2.0, not to mention 3.0, 4.0,...

The color map:

color_map {
[0.00 color rgb <0.19, 0.41, 0.89>]
[0.20 color rgb <0.22, 0.34, 0.62>]
[0.40 color rgb <0.17, 0.44, 0.55>]
[0.60 color rgb <0.22, 0.47,0.40>]
[0.80 color rgb <0.56, 0.33, 0.24>]
[1.00 color rgb <0.7, 0.15,0.08>]
}
```

Attachments:

Preview of image 'raidal composite degradation.png'

 From: And Subject: Re: A radial pattern contains randomize(bump) Date: 27 Aug 2023 02:55:00 Message:
```
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"@context": "https://schema.org",
"@type": "DiscussionForumPosting",
"@id": "#web.64eaf31624fd44d94b51e394aa81652d%40news.povray.org",
"dateCreated": "2023-08-27T06:55:00+00:00",
"datePublished": "2023-08-27T06:55:00+00:00",
"author": {
"@type": "Person",
"name": "And"
}
}
This one is a more special function.

Just like before, the function "f_freq_control_test" is what the output image
shows. And the color_map the same.

pigment {
function {f_freq_control_test(x,y,z)}
color_map {
[0.00 color rgb <0.19, 0.41, 0.89>]
[0.20 color rgb <0.22, 0.34, 0.62>]
[0.40 color rgb <0.17, 0.44, 0.55>]
[0.60 color rgb <0.22, 0.47,0.40>]
[0.80 color rgb <0.56, 0.33, 0.24>]
[1.00 color rgb <0.7, 0.15,0.08>]
}
}
```

Attachments:

Preview of image 'bump function power 1-x2.png'

 From: And Subject: Re: A radial pattern contains randomize(bump) Date: 27 Aug 2023 03:30:00 Message:
```
{
"@context": "https://schema.org",
"@type": "DiscussionForumPosting",
"@id": "#web.64eafae324fd44d94b51e394aa81652d%40news.povray.org",
"dateCreated": "2023-08-27T07:30:00+00:00",
"datePublished": "2023-08-27T07:30:00+00:00",
"author": {
"@type": "Person",
"name": "And"
}
}
Because my mathematics is not so good, so I need spend so many years to think
these composite(I just try something I prepare for other concept).

The result yesterday is surprising me.
```

Attachments:

Preview of image 'ellipse bump function.png'

 From: Thomas de Groot Subject: Re: A radial pattern contains randomize(bump) Date: 27 Aug 2023 07:31:00 Message: <64eb33f4@news.povray.org>
```
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"dateCreated": "2023-08-27T11:31:00+00:00",
"datePublished": "2023-08-27T11:31:00+00:00",
"author": {
"@type": "Person",
"name": "Thomas de Groot"
}
}
Op 26-8-2023 om 11:14 schreef And:
> I suddenly solve an important problem. About how to generate a circle associated
> pattern.
>
> I need such a pattern for my wood-pattern generator.
> For wood heart, I don't have good function in the past. But these series opens a
> window.

I think you are doing alright with this series of experiments.
Integrating these functions (or combination of functions) in your
wood-pattern generator will be interesting. Have you already done this?
I would be interested to see how that looks.

--
Thomas
```
 From: Bald Eagle Subject: Re: A radial pattern contains randomize(bump) Date: 27 Aug 2023 12:30:00 Message:
```
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"dateCreated": "2023-08-27T16:30:00+00:00",
"datePublished": "2023-08-27T16:30:00+00:00",
"author": {
"@type": "Person",
"name": "Bald Eagle"
}
}
"And" <49341109@ntnu.edu.tw> wrote:
> I suddenly solve an important problem. About how to generate a circle associated
> pattern.
>
> I need such a pattern for my wood-pattern generator.
> For wood heart, I don't have good function in the past. But these series opens a
> window.

Hi And,

These are interesting pattern experiments, and I'm looking forward to seeing
what you come up with.

I find it interesting to see the pattern that you have here, as I didn't
understand how the effect was being generated from a circular base pattern.

I coded your pattern into a scene, and for some reason, did not get the same
result.  Perhaps you could post the full code of a working scene.

Also, if you could describe the exact type of pattern that you are looking to
make, it would be easier to help you develop something through a logical
elaboration of a base pattern function.

I started with an atan2 (x, y) function, as that will give you a radial pattern

#version 3.8;
global_settings {assumed_gamma 1.0}
default {finish {diffuse 1}}

#include "functions.inc"

camera {
location <0, 0, -10>
right     x*image_width/image_height
up y
look_at <0, 0, 0>

}

light_source {<0,  1, -50> rgb 1.0}
sky_sphere {pigment {rgb 1}}

#declare C = function {0.5 - sqrt (x*x+y*y) + 0.1}

#declare W1 = function {f_bumps (x/C(x, y, z), y/C(x, y, z), z)}

#declare Freq = 20;
#declare Ang = function {atan2 (x, y)/(tau/Freq)}

#declare W2 = function {f_bumps (Ang (x, y, z), Ang (x, y, z), z)}

#declare Wood1 =
color_map {
[0.00 srgb <249, 210, 173>/255]
//[0.25 srgb <249, 210, 173>/255]

[0.25 srgb <252, 156, 173>/255]
//[0.50 srgb <252, 156, 173>/255]

[0.50 srgb <206, 126,  72>/255]
//[0.75 srgb <206, 126,  72>/255]

[0.75 srgb <113,  51,  24>/255]
//[1.00 srgb <113,  51,  24>/255]

}

plane {z, 0 pigment {function {W1(x, y, z)} color_map {Wood1}} }

//plane {z, 0 pigment {function {W2(x, y, z)} color_map {Wood1}} }

Attached is what I get when I try to use the functions posted here.
```

Attachments:

 From: Alain Martel Subject: Re: A radial pattern contains randomize(bump) Date: 27 Aug 2023 13:30:41 Message: <64eb8841\$1@news.povray.org>
```
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"dateCreated": "2023-08-27T17:30:41+00:00",
"datePublished": "2023-08-27T17:30:41+00:00",
"author": {
"@type": "Person",
"name": "Alain Martel"
}
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Le 2023-08-27 à 03:27, And a écrit :
> Because my mathematics is not so good, so I need spend so many years to think
> these composite(I just try something I prepare for other concept).
>
> The result yesterday is surprising me.

That's not surprising for me. That's a formula for an ellipse that you
got there for f_external_field.
```
 From: And Subject: Re: A radial pattern contains randomize(bump) Date: 28 Aug 2023 10:10:00 Message:
```
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"@context": "https://schema.org",
"@type": "DiscussionForumPosting",
"@id": "#web.64eca9e624fd44d989131d8aaa81652d%40news.povray.org",
"dateCreated": "2023-08-28T14:10:00+00:00",
"datePublished": "2023-08-28T14:10:00+00:00",
"author": {
"@type": "Person",
"name": "And"
}
}
Thomas de Groot <tho### [at] degrootorg> wrote:
> I think you are doing alright with this series of experiments.
> Integrating these functions (or combination of functions) in your
> wood-pattern generator will be interesting. Have you already done this?
> I would be interested to see how that looks.
>
> --
> Thomas

Thank you... I have not integrated these function with my wood-pattern generator
yet.

In fact, I'm not sure the shape of such patterns in three dimensions. I need
researching and think more.
```