[vtkusers] Displaying vtkPolyData while writing on it within Qt objects (QVTKWidget)

[Clinton Stimpson]

A QTimer doesn't require threads, only an active event loop.
If QTimer is the reason you are going multi-threaded, you've just make 
it harder on yourself.
Maybe you can you start from a VTK/Qt example and add a timer?

Clint

On 06/21/2010 01:47 AM, Barth, Sebastian wrote:
> Hello Clint,
>
> yes, I call Modified() and it's working, but that's not the problem. The point ist that Qt does not invoke the QTimer event while the mouse is moving. This is a Qt problem and I guess I have to use different threads to avoid this: One for the interface with the QVTKWidget and one for the QTimer which forces the manipulation of the vtkPolyData. I don't know if there is a better way.
>
> For this I want to know if there are some things I have to know if I want to have access to one vtkPolyData from out two different threads (QThread). There are few informations about QThread and almost none about VTK at a multithreading point.
>
> I hope someone can give me some instructions, because I know almost nothing about threads in this scope (VTK + Qt).
>
> Thanks a lot
>
> Sebastian
>
> -----Ursprüngliche Nachricht-----
> Von: vtkusers-bounces at vtk.org [mailto:vtkusers-bounces at vtk.org] Im Auftrag von Clinton Stimpson
> Gesendet: Freitag, 18. Juni 2010 22:23
> An: vtkusers at vtk.org
> Betreff: Re: [vtkusers] Displaying vtkPolyData while writing on it within Qt objects (QVTKWidget)
>
> On Friday, June 18, 2010 09:22:42 am Barth, Sebastian wrote:
>    
>> Hello vtkusers,
>>
>> my application uses the QVTKWidget with Qt 4.6.2 and VTK 5.6.0 as a part of
>> it's window.
>>
>> I have a 3D visualisation of a cluster of points stored in a vtkPolyData.
>> On my Qt window I can start a QTimer whose timeout() signal is connected
>> to a slot which manipulates the points in the vtkPolyData and updates the
>> visualisation pipeline with QVTKWidget::update().
>>
>> My vtkRendererWindow uses the default interactor style (trackball camera).
>>
>> While moving the camera (mouse interaction) the QVTKWindow gets updated,
>> but the vtkPolyData does not. This of course, is a Qt problem, but I want
>> to know if I have to do anything special if I want to write on the
>> vtkPolyData object from out another thread (QThread) while I'm moving the
>> camera and displaying the current written Data. Maybe there is a simplier
>> solution, I don't know!
>>
>> It's the first time I work with VTK, QT and even threads and I appreciate
>> every help!
>>
>>      
> Are you calling Modifed() on the vtkPolyData after modifying its points?
>
> Clint
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