vtkUnstructuredGrid in mayavi jupyter-notebook with x3d backend

Hello,

I have a problem with `vtkUnstructuredGrid` (notably vtk output file from OpenFOAM) visualization in *jupyter-notebook* using *mayavi mlab* tools.
I tried to visualize my .vtk file in two ways - via *mayavi standalone* and via embedded notebook window. Below is my code in *jupyter-notebook*.
The first way (*mayavi standalone*) is successful, when I try to do the second one I get the non-responding white window in my notebook.
Here is the code for internal (jupyter) visualization:
```python
mlab.init_notebook(local=True,width=700,height=700)
fig = mlab.figure()
src = mlab.pipeline.open('./cavity/VTK/cavity_100.vtk')
o = mlab.pipeline.outline(src)
fig
```
And here is the error which I get in terminal where the jupyter-notebook is loaded:
```
[W 12:26:57.383 NotebookApp] 404 GET /notebooks/OpenFOAM/cavity/x3dom.swf (127.0.0.1) 1.39ms referer=http://localhost:8888/notebooks/OpenFOAM/cavity/cavity_mayavi_test.ipynb
```
The test involving the visualization of *polydata* vtk format in *jupyter-notebook* passed successfully.

Best Regards,
Delcraft