Change square to circle in Three.js PointCloud?

I am loading a .ply file using PLYLoader and rendering it using PointCloud object in three.js file.

var loader = new THREE.PLYLoader();
loader.addEventListener('load', function (event) {
    var geometry = event.content;
    var material = new THREE.PointCloudMaterial({ vertexColors: true, size: 0.01 });
    var mesh = new THREE.PointCloud(geometry, material);
    scene.add(mesh);
});
loader.load(file_url);

      

        
        
        
      

    

Works fine, dots are displayed correctly. However, the points are displayed as a square. Can I change them to a circle? If so, how?

I found this old thread that shows an image of three.js sample. We can clearly see the circles. However, which in the same sample today shows the squares (after they changed the ParticleSystem to PointCloud).

thank