title: Thee.js. textures from canvas refers to the lastone
body: <p>I'm creating some textures for a tiled map. 
  I have 10 images. I put every one on canvas (to see it), then create a texture from canvas.
  I think there is some persitent link to the canvas because the 10 textures created  are equal to another (the last one).</p>
  
  <p>Are three.js saving some information relative to the canvas and the 'neeedsUpdate' means that the same canvas is used ? (and if the process is fast I have the same canavas image for every one of 10 ?)</p>
  
  <p>Any idea ? Thanks</p>