title: How to get pixels from computed texture in three js?
body: <p>I need to compute a multidimensional array of data, and I think GPUComputationRenderer is a good solution for that.</p>
  
  <p>I started from an example project and was stuck on this:</p>
  
  <pre><code>var gpuCompute = new GPUComputationRenderer( 100, 100, this.renderer );
  
  var dtPosition = gpuCompute.createTexture();
  var dtVelocity = gpuCompute.createTexture();
  
  var velocityVariable = gpuCompute.addVariable( 
     "textureVelocity", 
     this.compFragmentShader(), 
     dtVelocity 
  );
  var positionVariable = gpuCompute.addVariable( 
     "texturePosition", 
     this.compVertexShader(),   
     dtPosition 
  );
  
  gpuCompute.setVariableDependencies( 
     velocityVariable, 
     [ positionVariable, velocityVariable ] 
  );
  gpuCompute.setVariableDependencies( 
     positionVariable, 
     [ positionVariable, velocityVariable ] 
  );
  
  gpuCompute.init();
  
  gpuCompute.compute();
  
  //TODO: Get pixels from resulting texture
  </code></pre>
  
  <p>I had read some examples on three.js:</p>
  
  <ul>
  <li><a href="https://threejs.org/examples/?q=water#webgl_gpgpu_water" rel="nofollow noreferrer">https://threejs.org/examples/?q=water#webgl_gpgpu_water</a></li>
  <li><a href="https://threejs.org/examples/?q=gp#webgl_gpgpu_birds" rel="nofollow noreferrer">https://threejs.org/examples/?q=gp#webgl_gpgpu_birds</a></li>
  <li><a href="https://github.com/mrdoob/three.js/blob/master/examples/jsm/misc/GPUComputationRenderer.js" rel="nofollow noreferrer">https://github.com/mrdoob/three.js/blob/master/examples/jsm/misc/GPUComputationRenderer.js</a></li>
  </ul>
  
  <p>Also, I had read this stack overflow <a href="https://stackoverflow.com/questions/39736203/three-js-read-pixels-from-gpucomputationrenderer-texture?rq=1">THREE.js read pixels from GPUComputationRenderer texture</a> but there is no solution, only links to webGL.</p>
  
  <p>Am I missing something?
  Please provide an example or describe what am I doing wrong</p>