anchor.diff:          points.addAll([xmin, ymax, zmax]);
           points.addAll([xmax, ymax, zmax]);
   
  -        // Y
  -        points.addAll([xmin, ymin, zmin]);
  -        points.addAll([xmin, ymax, zmin]);
  -        points.addAll([xmax, ymin, zmin]);
  -        points.addAll([xmax, ymax, zmin]);
  -        points.addAll([xmin, ymin, zmax]);
  -        points.addAll([xmin, ymax, zmax]);
  -        points.addAll([xmax, ymin, zmax]);
  -        points.addAll([xmax, ymax, zmax]);
  -
  -        // Z
  -        points.addAll([xmin, ymin, zmin]);
  -        points.addAll([xmin, ymin, zmax]);
  -        points.addAll([xmax, ymin, zmin]);
  -        points.addAll([xmax, ymin, zmax]);
  -        points.addAll([xmin, ymax, zmin]);
  -        points.addAll([xmin, ymax, zmax]);
  -        points.addAll([xmax, ymax, zmin]);
  -        points.addAll([xmax, ymax, zmax]);
  +        points.addAll([xmin + (xmax-xmin)/2, ymin + (ymax-ymin)/2, ymin + (ymax-ymin)/2]);
  +
  +        final int numPoints = points.length ~/ 3;
  +
  +        var xx = new Float32List(numPoints);
  +        var yy = new Float32List(numPoints);
  +        var zz = new Float32List(numPoints);
   
           for (int i = 0; i < numPoints; i++) {
               xx[i] = points[i * 3];
               yy[i] = points[i * 3 + 1];
               zz[i] = points[i * 3 + 2];
           }
  +
  +        Map<String, Float32List> map = new Map();
  +        map["positions.x"] = xx;
  +        map["positions.y"] = yy;
  +        map["positions.z"] = zz;
   
           var cloud = new PointCloud("oldcube");
           cloud.addDimensions(map);
  
positive.code: 
          List points = [];
  
          // X
          points.addAll([xmin, ymin, zmin]);
          points.addAll([xmax, ymin, zmin]);
          points.addAll([xmin, ymax, zmin]);
  
negative.code: 
  
      static PointCloud makeOldCube() {
  
          double xmin = -100.0;
          double xmax = 100.0;
          double ymin = -100.0;
          double ymax = 100.0;
          double zmin = -100.0;
          double zmax = 100.0;
  
          // x = red
          // y = green
  