<p>The Flurry screensaver written by Calum Robinson is available as a part of the XScreenSaver package. You can download its source code from <a href="https://www.jwz.org/xscreensaver/download.html" rel="nofollow noreferrer">https://www.jwz.org/xscreensaver/download.html</a></p>

<p>The flurry* files are in the hacks/glx directory. It's not an easy job to reverse engineer the algorithm from the source code, but debugging might help.</p>

CC BY-SA 4.0
2018-11-02T21:08:20.193Z
2018-11-02T21:08:20.193Z
revl
<p>Looking at the video you provided, I would tend to think it's something along those lines:</p>

<ul>
<li>A particle emitter, to which all threads are attached, is moving around. I haven't really figured what its motion is dictated by.</li>
<li>Each thread is made of particles flowing away from the emitter. The thread has a direction, used for the initial speed of the particles. Once created,  they are independent from the emitter.</li>
<li>The particles use a quad or a rectangle textured with a fuzzy ellipse shape (you can see them individually when a thread suddenly changes direction) oriented in the direction of the motion. Their color is based on the duration since their creation, and they use additive alpha blending (the saturation to white is typical). After a certain duration, they fade out and die, only to be recycled into new particles.</li>
<li>I suspect the whole thing might be in a vector field, or something similar blowing wind onto the particles, which would explain why the threads sometimes suddenly change direction.</li>
<li>There might be some feedback post-processing effect to smooth everything out.</li>
</ul>

CC BY-SA 3.0
2016-04-09T09:10:49.433Z
2016-04-09T09:10:49.433Z
Julien Guertault
<p>I want to generate video similar to OSX Flurry screensaver (<a href="https://i.sstatic.net/2wCyP.png" rel="nofollow noreferrer">screenshot</a>, <a href="https://youtu.be/JWzBK87t19U" rel="nofollow noreferrer">video</a>), but I have no idea how it is made. Does anyone here has an idea about how it's made, its algorithm and method?</p>

CC BY-SA 3.0
2016-04-09T05:14:46.607Z
Could you narrow things down a bit. Like what have you tried. What is your level of expertise. Think of it thisway, if I were to answer you as briegly as you ask would you be happy?
joojaa
CC BY-SA 3.0
2016-04-09T10:27:03.123Z
I am pretty much a newbie, never touch cg before, just try to get some keywords so that I can google around and move forward. But details are welcomed too.
Ryan
CC BY-SA 3.0
2016-04-09T10:54:49.477Z
Problem is that since your question is high level you also get a high level answer that pobably does not help you much. The first step is hard. Not the what to do once you have it done.
joojaa
<algorithm>
How to generate OSX Flurry screensaver
Ryan
# How to generate OSX Flurry screensaver

(Asked by: username_0 on 2016-04-08)

I want to generate video similar to OSX Flurry screensaver ([screenshot](https://i.sstatic.net/2wCyP.png), [video](https://youtu.be/JWzBK87t19U)), but I have no idea how it is made. Does anyone here has an idea about how it's made, its algorithm and method?

**Tags:** algorithm

> **Comments:**
> **username_1**: Could you narrow things down a bit. Like what have you tried. What is your level of expertise. Think of it thisway, if I were to answer you as briegly as you ask would you be happy?  
> **username_0**: I am pretty much a newbie, never touch cg before, just try to get some keywords so that I can google around and move forward. But details are welcomed too.  
> **username_1**: Problem is that since your question is high level you also get a high level answer that pobably does not help you much. The first step is hard. Not the what to do once you have it done.  

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## 2 answers

### Answer by username_3 on 2016-04-09. Score: 6 | Accepted answer

Looking at the video you provided, I would tend to think it's something along those lines:

* A particle emitter, to which all threads are attached, is moving around. I haven't really figured what its motion is dictated by.
* Each thread is made of particles flowing away from the emitter. The thread has a direction, used for the initial speed of the particles. Once created, they are independent from the emitter.
* The particles use a quad or a rectangle textured with a fuzzy ellipse shape (you can see them individually when a thread suddenly changes direction) oriented in the direction of the motion. Their color is based on the duration since their creation, and they use additive alpha blending (the saturation to white is typical). After a certain duration, they fade out and die, only to be recycled into new particles.
* I suspect the whole thing might be in a vector field, or something similar blowing wind onto the particles, which would explain why the threads sometimes suddenly change direction.
* There might be some feedback post-processing effect to smooth everything out.


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### Answer by username_2 on 2018-11-02. Score: 3

The Flurry screensaver written by Calum Robinson is available as a part of the XScreenSaver package. You can download its source code from <https://www.jwz.org/xscreensaver/download.html>

The flurry\* files are in the hacks/glx directory. It's not an easy job to reverse engineer the algorithm from the source code, but debugging might help.


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