[Paraview] Can a collaborative client share a pipeline without creating a view itself?

[Utkarsh Ayachit]

Peter,

In ParaView's collaboration support there's the notion of a master and
everyone else. The first client that connects to the pvserver is the
"master" by default. The master is the only one that should create new
proxies. This doesn't preclude the other clients from not creating new
proxies, but if they do, things start acting funny. Also all client
have exactly the same views as the proxy. They can be showing a
different camera, but not have different number of views or types of
views etc.

> If I compile the example with "USEVIEW" defined in the beginning,
> a) Starting in the order pvserver->example->ParaView, ParaView reports "This
> code may not work in multi-clients mode. Could not locate server on which
> the source is being added." and shows the sphere in the renderer, but not in
> the pipeline panel.

There seems to be a bug where the ParaView client has trouble loading
existing state from another client. It seems to work as expected if
the "master" starts creating sphere etc. after the other client has
connected.

> c) Starting in the order pvserver->example->ParaView, ParaView reports
> "Could not locate server on which the source is being added." and shows
> nothing.

Same issue as (a).

> d) Starting in the order pvserver->ParaView->example, ParaView shows "Sph1"
> in the pipeline panel, but nothing in the renderer.

In this case your non-master example has created a view which is not supported.

> Why does the Sphere not show up in ParaView's pipeline panel in case a)?

A bug in loading initial collaboration state.

> Why does the Sphere show up in ParaView's pipeline panel, but not in the
> renderer in case d)?

You're showing sphere in a view not known to master.

> And what does "This code may not work in multi-clients mode" and "Could not
> locate server on which the source is being added" exactly wnat to tell me?

Proxies are being created before the session was "ready for use". Like
I said, collaboration isn't being used actively in production so such
issues are expected. Since I don't have active projects funding this,
I will try to track down the bug exposed by (a) and give you a fix
over the weekend if I can.

Utkarsh