title: three.js water surface following with object
body: <p>I'm using <a href="http://threejs.org/examples/webgl_gpgpu_water.html" rel="nofollow">"threejs-examples-webgl-gpgpu_water"</a> and would like to put an object on the surface following this surface which means sync with the vertex displacement on the point where the object is.</p>
  
  <p>I cannot find out how to get the current height of coordinates x,y in the water surface. I guess the image is calculated in the shader and there is no access to the intermediate value of the deformed water surface. Can someone help?</p>