void evaluatePixel()
      {        
          float2 pos = (outCoord() - center) / imgSize;
  
          float pi = 3.141592653589793;
          float a = atan(pos.y,pos.x);
          float r = sqrt(pow(pos.x,2.0)+pow(pos.y,2.0));
          
          float u = 0.0;
          float v = 0.0;
          float w = 0.0;
          
          u += offset.x;
          v += offset.y;