How to load a CAD model file with IGS or GLB format, extract and convert to point cloud/mesh format file.

### 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

How to load a CAD model file with IGS or GLB format, extract and convert to point cloud/mesh format file with python.

I look up from document, google, stackoverflow, but there is no useful information to do it.

It will display blank page with code below.

```python
model = o3d.io.read_triangle_mesh(src)
model.compute_vertex_normals()
o3d.visualization.draw_geometries([model])
```