How to improve the quality of pts file with xyzi or xyzirgb data visualization?

### Checklist

- [X] I have searched for [similar issues](https://github.com/isl-org/Open3D/issues).
- [X] For Python issues, I have tested with the [latest development wheel](http://www.open3d.org/docs/latest/getting_started.html#development-version-pip).
- [X] I have checked the [release documentation](http://www.open3d.org/docs/release/) and the [latest documentation](http://www.open3d.org/docs/latest/) (for `master` branch).

### My Question

Hello open3d team,

I am using Python Open3d.
I am using data in the format:
```
371349.850 796969.999 65.526 215
371349.852 796969.999 65.525 219
371349.853 796969.999 65.525 218
371349.854 796969.999 65.526 216
371349.855 796969.999 65.526 217
371349.856 796969.999 65.526 220
371349.857 796969.999 65.526 223
371349.859 796969.999 65.526 226
371349.860 796969.999 65.526 220
371349.861 796969.999 65.527 211
371349.862 796969.999 65.526 214
371349.864 796969.999 65.525 218
371349.865 796969.999 65.525 219
371349.867 796969.999 65.525 220
```
my code to load and visualize these files is:
~~~
with open(file_name, "r") as f:
for line in f:
if len(line.split()) == 4:
x, y, z, i = [num for num in line.split()]
points_np.append([float(x), float(y), float(z), float(I)])
print('loop end')
points_arr = np.array(points_np).transpose()
print(len(points_arr))
point_xyz = points_arr[:3].transpose()
print("xyz points shape", point_xyz.shape)
pcd = o3d.geometry.PointCloud()
pcd.points = o3d.utility.Vector3dVector(point_xyz)
if len(points_arr) == 4:
points_intensity = (points_arr[3])/255.0
print("intensity points len", points_intensity.shape)
points_intensity_rgb = np.vstack((points_intensity,
points_intensity,
points_intensity)).T
print("intensity_rgb points shape", points_intensity_rgb.shape)
pcd.colors = o3d.utility.Vector3dVector(points_intensity_rgb)
# Visualization
o3d.visualization.draw_geometries([pcd])
~~~
The quality of the visualisation I am getting is much worse compared to other visualisation apps (like CloudCompare which is using open3d as well).
Could you please suggest how I can improve on visualization quality or change my code to make the visualisation look better?