[Paraview-developers] Interaction with server data within client plugin
Matthias Schneider
schneider at vision.ee.ethz.ch
Wed May 8 14:00:52 EDT 2013
Hi Sebastien,
again, thanks for your help!
I guess now I'm totally lost... So you're suggesting to make the active
node coordinate part of the internal state of the pure vtk class and
access it as a proxy property from the client side with the
information_only flag enabled?
At what point will this property be updated? I rather thought this will
be done in one of the GetActiveNodeCoord variants, something like
double* vtkMyDataHandler::GetActiveNodeCoord() {
return m_data->GetPoint(m_nodeId);
}
This of course assumes that the input and node id property have been set
properly by the client. Obviously, I am still missing part of the design
here?!
As for the wrapping I get even more confused. Is it really true that the
header files/class defintions are specifically parsed for the appearance
of the vtkSet/Get*Macros? At least I obtain different results when I use
vtkGetVector3Macro and a manual expansion of the macro with exactly
the same definitions. In all cases only one of the get methods are wrapped.
With the macro, the client server wrapper calls
virtual double *GetActiveNodeCoord()
with the expansion, the wrapper invokes
virtual void GetActiveNodeCoord (double _arg[3])
Best,
matthias
On 05/08/2013 04:33 PM, Sebastien Jourdain wrote:
> Hi Matthias,
>
> you should use the following set of macro inside your vtkObject
>
> public:
> vtkSetVector3Macro(ActiveNodeCoord, double);
> vtkGetVector3Macro(ActiveNodeCoord, double);
>
> protected:
> double ActiveNodeCoord[2];
>
> This should solve your wrapping issue.
>
>
> On Wed, May 8, 2013 at 9:39 AM, Matthias Schneider
> <schneider at vision.ee.ethz.ch <mailto:schneider at vision.ee.ethz.ch>> wrote:
>
> Hi,
>
> Thanks for the useful hints. I have implemented the vtk class to
> interact with the vtk data object on the server side and use a proxy
> to interact with it from the client side as suggested by Sebastien -
> thanks! However, I'm still struggling with the proper xml definition
> for the proxy. Also there seems to be an issue with the
> Client/Server wrapper (see below).
>
> The pure vtk class has the interface:
>
> class vtkMyDataHandler: public vtkObject {
> public:
> [...]
> void SetInput(vtkAlgorithm* src);
> void SetActiveNode(vtkIdType id);
>
> double* GetActiveNodeCoord();
> void GetActiveNodeCoord(double coord[3]);
> [...]
> private:
> [...]
> vtkPolyData* m_data;
> vtkIdType m_nodeId;
> };
>
> The Set* methods are used to define a vtkAlgorithm with a
> vtkPolyData output and a particular node/vertex id within the
> vtkPolyData. Eventually, the handler is supposed to return the node
> coordinates (x,y,z) of the selected vertex within the data set.
>
> The xml descriptor for the class looks like this:
>
> <ServerManagerConfiguration>
> <ProxyGroup name="utility">
> <Proxy name="MyProxy" class="vtkMyDataHandler" label="Data Handler">
> <ProxyProperty name="Input"
> command="SetInput" />
>
> <IdTypeVectorProperty name="ActiveNode"
> command="SetActiveNode"
> default_values="-1"
> number_of_elements="1" />
>
> <DoubleVectorProperty command="GetActiveNodeCoord"
>
> default_values="0.0 0.0 0.0"
> information_only="1"
> name="ActiveNodeCoord"
> number_of_elements="3" />
> </Proxy>
> </ProxyGroup>
> </ServerManagerConfiguration>
>
> On the client side I do the following:
>
> // set up proxy on the client side
>
> vtkSMProxyManager *pxm = vtkSMProxyManager::__GetProxyManager();
> vtkSMProxy *proxy = pxm->NewProxy("utility", "MyProxy");
>
> // set internal state of proxy
> vtkSMPropertyHelper(proxy,"__Input").Set(properInputProxy);
> vtkSMPropertyHelper(proxy,"__ActiveNode").Set(1);
> proxy->UpdateVTKObjects();
>
> // obtain information from proxy
> proxy->UpdateProperty("__ActiveNodeCoord")
> double tmp[3] = { -1.0, -1.0, -1.0 };
> vtkSMPropertyHelper(proxy, "ActiveNodeCoord").Get(tmp, 3);
>
>
> Setting up the proxy and its initial state works perfectly fine.
> However, I am not able to update the desired property and invoke the
> call of vtkMyDataHandler::__GetActiveNodeCoord.
>
> There are two issues that I came accross here.
>
> 1) There seems to be a problem (?) with the Client/Server wrapper.
> For some reason the method without any argument
>
> double* GetActiveNodeCoord();
>
> does not get wrapped in vtkMyDataHandlerClientServer.__cxx
> This leads to an error if I change the update command to:
>
> proxy->__UpdatePropertyInformation(__proxy->GetProperty("__ActiveNodeCoord"));
>
> ERROR:
> In[...]/ParaView-3.98.1-__source/ParaViewCore/__ServerImplementation/Core/__vtkPVSessionCore.cxx,
> line 389
> vtkPVSessionCore (0x2aa9de0): Object type: vtkMyDataHandler, could
> not find requested method: "GetActiveNodeCoord"
> or the method was called with incorrect arguments.
>
> while processing
> Message 0 = Invoke
> Argument 0 = vtk_object_pointer {vtkMyDataHandler (0x29cc970)}
> Argument 1 = string_value {GetActiveNodeCoord}
>
> 2) With the update command used in the code snippet, the property
> values are set to the default values but the data handler function
> (GetActiveNodeCoord) doesn't get called as information only
> properties cannot be updated according to vtkSMProxy::UpdateProperty.
>
> So maybe I have a wrong understanding of information only
> properties?! I had a look at some of the xml examples in utilities.xml
> (ParaView-3.98.1-source/__ParaViewCore/ServerManager/__SMApplication/Resources/__utilities.xml)
> and it seemed to me like this is the way to go?!
>
> Removing the information_only tag from the xml property descriptor,
> the property obviously gets updated in proxy->UpdateVTKObjects(),
> which for obvious reasons results in an error as there is no method
> to *set* the node coordinates.
>
> So what am I missing here? I would be really happy about any kind of
> comments or hints how to do this.
>
> Best,
> Matthias
>
>
>
> On 04/05/2013 03:25 PM, Sebastien Jourdain wrote:
>
> Hi Matthias,
>
> However, getting access to the vtkPolyData object on the
> server will not be possible that easily I guess.
>
>
> From the client side, not really unless you know that you will
> only run
> in a built-in session.
> That's precisely why you need to create a pure VTK class that
> will be
> connected in some way to that object from the client side via proxy
> while the real connection will happen on the server side.
>
> I guess there is some kind of vtk algorithm required on the
> server side
>
> to do the processing which is configured from the client via a
> proxy.
>
> Yes, although it doesn't need to be an algorithm if it is not a
> 'filter'
> type of object.
> But for instance you can create a VTK class that will provide an API
> like that:
>
> SetMyVtkObjectToLookInto(__vtkObject* whatYouWant)
> SetActiveNodeId(int id)
> double* GetNewCenterOfRotation()
>
> And on the client side thanks to proxy (You will need to write a
> small
> XML file for your VTK class) you will have to write something
> like that.
>
> myProxy = pxm.NewProxy('utility','__mySuperProxy');
> vtkSMPropertyHelper(myProxy, 'ProxyPropName').Set(
> yourProxyThatYouSelectedFromTh__eUI );
> vtkSMPropertyHelper(myProxy, 'ActiveNode').Set( yourSelectedID );
> myProxy->UpdateVTKObjects(); // This will push the changes to
> the server
>
> // Now it's time to retreive the info from the server
> myProxy->__UpdateInformationProperty('__CenterOfRotation');
> vtkSMPropertyHelper(myProxy, 'CenterOfRotation').Get(
> localArrayToFillWithCenterOfRo__tation );
>
> Hope this give you a feeling on how the things works...
>
> Seb
>
> PS: I just wrote things from the top of my head, so names might not
> exactly match but the idea is there.
>
>
>
> On Fri, Apr 5, 2013 at 8:48 AM, Matthias Schneider
> <schneider at vision.ee.ethz.ch
> <mailto:schneider at vision.ee.ethz.ch>
> <mailto:schneider at vision.ee.__ethz.ch
> <mailto:schneider at vision.ee.ethz.ch>>> wrote:
>
> Hi Sebastian!
>
> Thank you very much for you quick answer!
> I don't have any server side class yet.
>
> I used the DockWidget example to setup a GUI (QDockWidget)
> along
> with some simple elements:
> pqOutputPortComboBox: define source
> QSpinBox: define node id
> QPushButton: trigger event
>
> As I understand it the whole GUI processing takes place at the
> client side and has access to the server data via proxies only.
>
> To stick with my simple example, I'd need a way to actually
> access
> the server source, which is a vtkPolyData in my case
> (originating
> from an exported graph, i.e., nodes connected by lines).
>
> // Get source from pqOutputPortComboBox
> [...]
> vtkSMSourceProxy *source = ...
>
> // obtain requested node id from GUI element
> vtkIdType nodeId = [...]
>
> // If we had access to the vtkPolyData itself, we could do
> sth like...
> vtkPolyData *data = ...
> double coord[3];
> data->GetPoints()->GetPoint(____nodeId, coord);
>
>
> // Set rotation center of current view to coord and render view
> [...]
>
> However, getting access to the vtkPolyData object on the
> server will
> not be possible that easily I guess. I guess there is some
> kind of
> vtk algorithm required on the server side to do the
> processing which
> is configured from the client via a proxy (set the desired
> source
> and the node id). But as I said, I do not fully understand the
> ServerManager concept here and couldn't find any similar
> examples.
>
> Hope this helps to clarify my problem...
>
> Thanks for your help,
> Matthias
>
>
>
> On 04/05/2013 01:47 PM, Sebastien Jourdain wrote:
>
> Hi Matthias,
>
> I guess, you already have your vtk class that will do the
> processing on
> the server side ?
> If so what are the methods that you want to get called
> and with what
> arguments ?
>
> Then once, I know more about your special use case, I
> can dive
> into the
> server manager part properly...
>
> Seb
>
>
> On Fri, Apr 5, 2013 at 7:16 AM, Matthias Schneider
> <schneider at vision.ee.ethz.ch
> <mailto:schneider at vision.ee.ethz.ch>
> <mailto:schneider at vision.ee.__ethz.ch
> <mailto:schneider at vision.ee.ethz.ch>>
> <mailto:schneider at vision.ee.
> <mailto:schneider at vision.ee.>____ethz.ch <http://ethz.ch>
>
> <mailto:schneider at vision.ee.__ethz.ch
> <mailto:schneider at vision.ee.ethz.ch>>>> wrote:
>
> Hi,
>
> I'm trying to implement an extension for Paraview
> but I'm
> somewhat
> stuck with the client/server and ServerManager
> concepts used in
> Paraview. Maybe someone could give a hint where to
> find
> some more
> information on that. I was looking at the plugin
> examples
> but that
> didn't help me too much.
>
> What I do not understand is how to establish some
> kind of data
> transfer between the server and the client. A very
> simple
> example
> that I was trying to implement is as follows: For a
> vtkPolyDataSet
> source define a point id via a GUI element and set
> the rotation
> center of the active view to the coordinate of
> this point.
>
> Based on the DockWidget example and the
> SelectionInspector
> I was
> able to create the GUI elements on the client side
> to select an
> appropriate source on the server side and get
> access to the
> active
> view. What I do not understand is how to interact
> with the
> actual
> data of the source to read the spatial coordinates
> of the
> user-defined vertex.
>
> On the client side I use a pqOutputPortComboBox to
> select
> the source
> which gives access to the current
> pqOutputPort/pqPipelineSource.
> >From this I get a
> vtkSMSourceProxy/______vtkPVDataInformation which
>
>
> allows me to read basic information of the data as
> shown in
> Paraview's statistics inspector (no. of cells/points,
> memory size,
> bounds, ...).
>
> Can anybody give me a hint how to do this
> properly? Any help is
> appreciated very much.
>
> Thanks,
> Matthias
>
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>
> --
> Matthias Schneider
> Computer Vision Laboratory
>
> ETH Zürich, ETF D114.1
> Sternwartstrasse 7
> 8092 Zürich, Switzerland
>
> fon: +41 44 63 20379 <tel:%2B41%2044%2063%2020379>
> <tel:%2B41%2044%2063%2020379>
> fax: +41 44 63 21199 <tel:%2B41%2044%2063%2021199>
> <tel:%2B41%2044%2063%2021199>
> www.vision.ee.ethz.ch/~____schneima/
> <http://www.vision.ee.ethz.ch/~__schneima/>
> <http://www.vision.ee.ethz.ch/__~schneima/
> <http://www.vision.ee.ethz.ch/~schneima/>>
>
>
--
Matthias Schneider
Computer Vision Laboratory
ETH Zürich, ETF D114.1
Sternwartstrasse 7
8092 Zürich, Switzerland
fon: +41 44 63 20379
fax: +41 44 63 21199
www.vision.ee.ethz.ch/~schneima/
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