Plasma effect

<h2 id="synopsis">Synopsis</h2>

<p>As there are many "hacked" approaches for implementing a plasma effect, this outline of an algorithm will just describe the theoretical basis for the effect. In order to achieve a sufficiently fast and good-looking real-time implementation (especially on the limited hardware available at the time this effect was at the height of its popularity in the 1990s), one would often do "non-correct" approximations to this algorithm. This, however, can often be done without noticeable visual differences.
</p><p>This algorithm is given in two dimensions, but could easily be adopted to any number of dimensions or any number of color channels.
</p><p>Let 
  
    
      
        f
        (
        x
        ,
        y
        )
      
    
    {\displaystyle f(x,y)}
  
 be a multi-frequency noise function of two variables (<i>e.g.</i>, a <a href="/facts/Perlin_noise/Eg48246G">Perlin noise</a> function). Let each color component 
  
    
      
        c
      
    
    {\displaystyle c}
  
 at the pixel 
  
    
      
        (
        x
        ,
        y
        )
      
    
    {\displaystyle (x,y)}
  
 be a linear function of the expression 
  
    
      
        sin
        ⁡
        (
        f
        (
        x
        ,
        y
        )
        ∗
        
          
            freq
          
          
            c
          
        
        )
      
    
    {\displaystyle \sin(f(x,y)*{\text{freq}}_{c})}
  
. Increasing the value of the constant 
  
    
      
        
          
            freq
          
          
            c
          
        
      
    
    {\displaystyle {\text{freq}}_{c}}
  
 tends to increase the steepness of the color gradients in the image.
</p>
<h2 id="see-also">See also</h2>
<p><a href="/facts/Diamond-square_algorithm/k3hhV2Vm">Diamond-square algorithm</a> is the fractal used by the original Plasma demo, and is now often called the plasma fractal which was the name given to it in Fractint.
</p>

<h2 id="external-links">External links</h2>
<ul><li><a href="http://www.bidouille.org/prog/plasma">Page explaining how the effect is built and including a JavaScript animation</a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>"What are the main concepts behind building the plasma effect with GSLS?". Computer Graphics Stack Exchange. Retrieved 2024-09-09. <a href="https://computergraphics.stackexchange.com/questions/13074/what-are-the-main-concepts-behind-building-the-plasma-effect-with-gsls" target="_blank">https://computergraphics.stackexchange.com/questions/13074/what-are-the-main-concepts-behind-building-the-plasma-effect-with-gsls</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
</ol>

Plasma effect open-in-new

Plasma effect