title: three.js - Adjusting opacity of individual particles
body: <p>I am trying to vary the opacity of particles as a function of their distance from a plane.</p>
  
  <p><a href="https://github.com/mrdoob/three.js/issues/297" rel="noreferrer">This issue</a> describes my problem, and the answer a year ago was essentially <em>"you can't"</em>. Opacity is apparently a parameter of a material, not an element, and hence individual particle opacity is not possible.</p>
  
  <p>Has anything changed, is there any way I could achieve this? If individual particle colouring is possible, I imagine this isn't out of reach.</p>
  
  <p>Cheers</p>