[Paraview] Object Panel <-> Model Communication

[Rafael March]

Thanks a lot Utkarsh,

I'm already testing and learning about the Information Properties, and I realized this is exactly what I need, concerning the Client/Server Communication.

Let me try to explain what I asked about the visualization pipeline: 
Suppose I have an unstructured grid.Then, my filter associate an integer number, from 0 to 6, to each cell, according to an algorithm. My filter also implements a custom object panel. Then I clip my model, through the Clip Filter. Is it possible to get the output of the Clip (that is, the nodes that weren't cutted off )from my custom filter code (which stays before the Clip filter in the pipeline) ?

Regards,
Rafael March.

--- On Tue, 12/16/08, Utkarsh Ayachit <utkarsh.ayachit at kitware.com> wrote:
From: Utkarsh Ayachit <utkarsh.ayachit at kitware.com>
Subject: Re: [Paraview] Object Panel <-> Model Communication
To: rafaelmarch3 at yahoo.com
Cc: paraview at paraview.org
Date: Tuesday, December 16, 2008, 2:17 PM

To get back "values" from the server, you can use either
"information
properties" or "information objects".

Information properties are properites with information_only="1" set
in
the XML (eg. in Servers/ServerManager/Resources/rendering.xml the
"Camera" proxy has "CameraPositionInfo" as an information
property).
Such properties need an "InformationHelper" which knows how to obtain
the values from the server. For simple Get*() methods, you can use the
<SimpleDoubleInformationHelper/> or <SimpleIntInformationHelper />
etc. based on the type of the property. Complex information helpers
can be written as well. Look at TimeStepsInformationHelper
(vtkSMTimeStepsInformationHelper.h|cxx) as an example.

Information objects are used to get data from server which cannot be
simply put in a property for example information about the data object
produced by a filter (vtkPVDataInformation). These are
vtkPVInformation subclasses. You can create you own vtkPVInformation
subclass that knows how to collect information and then
serialize/deserialize it for transfer to the client from the server
(if needed). To gather such information, one uses
vtkProcessModule::GatherInformation(vtkIdType connectionID,
vtkTypeUInt32 serverFlags, vtkPVInformation* info, vtkClientServerID
id) where "id" is vtkSMProxy::GetID() returned for the proxy from
which you want to collect the information.

In your case, information property may be an easier solution -- if I
understand your problem correctly.

There is a pqServerManagerModel instance accessible as
pqApplicationCore::instance()->getServerManagerModel() that can be
used to access sources/filters their representations, views etc. Take
a look at Qt/Core/pqServerManagerModel.h for the API. That should help
you access the visualization pipeline.

"How to get, for instance, the ids of the nodes which are displayed
after the application of a filter to the model ?"
Not sure I understand what you mean by that. Can you please elaborate?

Utkarsh

On Tue, Dec 16, 2008 at 6:38 AM, Rafael March <rafaelmarch3 at yahoo.com>
wrote:
> Hey all,
>
> I'm programming a filter with a custom Object Panel,
> and I'm feeling a little bit lost about the ParaView architecture and
> code design.
>
> My great problem is the comunication between the
> Object Panel and the Model. I know I can't have a pointer to my
> vtkUnstructuredGrid displayed, 'cause they are not necessarily at the
> same machine or process. I also know that I'm able to send information
> to the model through properties, since I can get the vtkSMProxy in my
> panel. But what about the way back ? Is there a way to send information
> from the display view to the panel ? How can I display in a QTable, for
> instance, the nodes of my model which have some property equals to 1 ?
>
> Another problem is the Visualization Pipeline: is there a way to
"walk" on
> it ?
> I mean, if I have a filter name, am I able to get the the filter no
> matter where it is in the Pipeline ?
>
> Sorry for the mess with the questions. I hope I made it clear and someone
> can help me ! :)
>
> Regards,
> Rafael March.
>
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>
>



      
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