anchor.diff:              case "/dir2/line.dat":
                   return _makeLine(webpath, displayName);
               case "/newcube.dat":
  -                return _makeNewCube(webpath, displayName);
  +                return _makeRandom(webpath, displayName);
               case "/oldcube.dat":
  -                return _makeOldCube(webpath, displayName);
  +                return _makeRandom(webpath, displayName);
               case "/dir1/random.dat":
                   return _makeRandom(webpath, displayName);
               case "/terrain1.dat":
  
positive.code:         map["positions.y"] = positionsY;
          map["positions.z"] = positionsZ;
  
          var xdim = 5000;
          var ydim = 5000;
          var zdim = 100;
  
          var xmin = -1000.0;
          var xmax = 1000.0;
          var ymin = -1000.0;
          var ymax = 1000.0;
          var zmin = 0.0;
          var zmax = 100.0;
  
          var random = new Random(17);
  
          for (int i = 0; i < numPoints; i++) {
              double d = i.toDouble() / numPoints.toDouble();
              double x = random.nextDouble();
              double y = random.nextDouble();
              double z = random.nextDouble();
  
              //x = y = z = d;
  
              x = xmin + (xmax - xmin) * x;
              y = ymin + (ymax - ymin) * y;
              z = zmin + (zmax - zmin) * z;
  
              positionsX[i] = x;
              positionsY[i] = y;
              positionsZ[i] = z;
          }
  
          var cloud = new PointCloud(webpath, displayName);
          cloud.createDimensions(map);
  
          return cloud;
      }
  
  
      static PointCloud _makeLine(String webpath, String displayName) {
          Map<String, Float32List> map = new Map();
  
negative.code:         throw new RialtoArgumentError("invalid file name");
      }
  
      static PointCloud _makeRandom(String webpath, String displayName) {
          Map<String, Float32List> map = new Map();
  
          var numPoints = 3;
  
          var positionsX = new Float32List(numPoints);
          var positionsY = new Float32List(numPoints);
  