JSON with polydata

[yh3ds]

Hello,
would it be possible to create a JSON containing a Polydata on backend server (running vtk through a Python script) and send it to vtk-js directly (using a json.dumps on server side) ?

When trying ot use it, I get this response : Object of type 'vtkPolyData' is not JSON serializable

Thanks a lot

[jourdain]

They are several way to do that. JSON is obviously one but not necessary the best one.

A better one could be using the vtp format to send a single binary blob over the network and use the XMLPolyDataReader on the vtk.js side.

If you use VTK and Python, you can use a synchronization mechanism that we rely on inside ParaView Visualizer to do local rendering. In that set up we inspect a RenderWindow and extract each actor geometry. We provide a scene descriptor in a JSON format and then the client request the various bits of arrays (coordinates, cells, fields) as binary blob. But this imply a more complex and connected relationship between the server and the client.

If JSON is your way to go, you can create a JSON format in Python that can be understand by vtk.js like described here.
Just provide a normal JSON array in the values field. When used with the vtk() function on the client side, such JSON will be converted to a vtkPolyData instance.

[yh3ds]

Thank you very much.

Have a nice day