POV-Ray : Newsgroups : povray.binaries.images : A radial pattern contains randomize(bump) : Re: A radial pattern contains randomize(bump) Server Time22 Sep 2023 05:20:26 EDT (-0400)
 Re: A radial pattern contains randomize(bump)
 From: Bald Eagle Date: 27 Aug 2023 12:30:00 Message:
```
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"headline": "Re: A radial pattern contains randomize(bump)",
"dateCreated": "2023-08-27T16:30:00+00:00",
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"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.
```

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