concentric circular gradient

I'm quite new to Filter Forge and I'm trying to get my head around how to create "repetitive concentric circular gradient" as I would call it. I've added an example of what I mean(manually created in PS). I need to be able to adjust the number of circles. The purpose is to use this a basis for a circular halftone filter.

Any pointers? Any suggestions?

Thanks in advance!

Joost

I know that there was a snippet that can make concentric circles like this, but I am sorry that at this moment i do not know where it is, if I find it i will put it here

Here are some methods to achieve concentric circles in FilterForge. Each of the methods have advantages and disadvantages so I thought I'd discuss some of that.

Method 1: Ellipse component - creates a circle, it doesn't break seamless tiling, but you can't move it in X and Y directions nor create a radius larger than the value of 100 (or 1)

Method 2: Free Ellipse component - Similar to the ellipse component but purposely breaks seamless tiling, allows you to move the circle anywhere you want (even off the screen), and lets you have any radius.

Method 3: Free Gradient - The free gradient lets you set the gradient X and Y starting and ending points, radial gradient was used. We can also remove the "black parts" by setting continuation from "flat" to "mirror" or otherwise. (This is probably what you're looking for).

Method 4 and 5 are just alternative ways. I can mention a bunch of reasons for doing those, but I think the 3 methods above should suffice.

Hope this helps!

Do note: a lot of the snippets are going out of date. Most of them exhibit stuff from 1.0 which lacked a lot of modern capabilities including the freedom to position anything anywhere and having the ability to break away from seamless tiling. [Clarifications] In effect, snippets are still a good resources. They're valid construction as far as it goes, but there are nicer / easier ways of dealing with complex shapes now .

Concentric Circles.ffxml

Thanks all for the great response!

@SpaceRay

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I have another possible method and is to make gradient stripes and then use the Polar Coordinates filters to make the circles.

This is indeed what I figured out. It does what I need.


@Skybase

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[Method 3: Free Gradient - The free gradient lets you set the gradient X and Y starting and ending points, radial gradient was used. We can also remove the "black parts" by setting continuation from "flat" to "mirror" or otherwise. (This is probably what you're looking for).

This is an even more elegant way to achieve a very similar result. However in this method I struggle how to create simple input sliders, as the line width is indirectly determined by (End x - Start x). I've figured out yet how I can do some simple algebra.... Perhaps any further pointers for this humble beginner?

Joost

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This is an even more elegant way to achieve a very similar result. However in this method I struggle how to create simple input sliders, as the line width is indirectly determined by (End x - Start x). I've figured out yet how I can do some simple algebra.... Perhaps any further pointers for this humble beginner?

Do you mean like offsetting the output in x and y coords?

Something like the screen cap below?

Note: while at it, I also recommend checking this page out on XY anchors. They're pretty key to how your filter would behave.
http://www.filterforge.com/more/help/...Works.html

I have found also a filter I have fr om Indigo Ray wh ere is shown an alternative way to make gradient shading concentric circles.

Here is the filter for FF 3.0

Concentric Circles.ffxml

Apart from the 3 posts above here I have also another different way I have done using the Polygon component and overlaying the circles but this works best with solid colors or images loaded than with gradients

Above I have suggested to make the concentric circles using Polar Coordinates, and here is the filter I have done to show how this can be done

Should note that the best input for "elevation" for "elevation gradient" should be black and white, not red.

I think I mentioned that to you somewhere else on these forums. Basically black and white is controllable compared to having all RGB values to deal with.

Speaking of concentric circles.... I dug out one of my past filters.

Let me make your life easier!

Simple method. It behaves.

Concentric Circle Variable.ffxml

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Skybase Let me make your life easier!

Thanks for the help and alternative way to do it, will see what I can do with it

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Simple method. It behaves

Sometimes there are different alternative ways to make the same or similar things, and sometimes something complex can be simplified doing the same in another different way, the important thing is that it behaves right and gets the result done