title: WebGL z-buffer artifacts?
body: <p>We are working on a Three.js based WebGL project, and have trouble understanding how transparency is handled in WebGL. The image shows a doublesided surface drawn with alpha = 0.7, which behaves correctly on its right side. However closer to the middle strange artifacts appear, and on the left side the transparency does not seem to work at all.</p>
  
  <p><a href="http://emilaxelsson.se/sandbox/vis1/alpha.png" rel="nofollow">http://emilaxelsson.se/sandbox/vis1/alpha.png</a></p>
  
  <p>The problem can also be seen here:
  <a href="http://emilaxelsson.se/sandbox/vis1/" rel="nofollow">http://emilaxelsson.se/sandbox/vis1/</a>
  Has anyone seen anything similar before? What could the reason be?</p>