[mitk-users] Pointless DisplayInteractor in VTK 3D render window

[Martin K. <mar...@hs...>]

Hi all,

I am currently working on implementing touch interactions in my QML
application. After I recognize gestures I send them to the display
interactor to process them. I adapted the display interactor to work for
GestureEvents. The events arrived but nothing was moving in the render
window. I though that my parameters are wrong. So I wanted to check the
parameters when a mouse event it handled.

The result were approximately the same values I already had before... So
I dug deeper... I made a test in an
void QmlMitkRenderWindowItem::mousePressEvent(QMouseEvent* me)
which is the equivalent to
void QmitkRenderWindow::mousePressEvent(QMouseEvent *me)

In there the incoming mouse event is converted into a mitk::mouseEvent
and then passed to the dispatcher to be handled. The dispatcher sends it
to display interactor to react. And at the end of the method the mouse
event is passed to the vtk widget/quick item:
QVTKWidget::mousePressEvent(me);
respectively
QVTKQuickItem::mousePressEvent(me);

So I was wondering why you have to pass the mouse event to vtk if the
display interactor is supposed to handle the event. I deactivated all
calls of this sort and then no interaction was working anymore!!!

That means that we have a display interactor for this render window but
in fact it has no influence on the interaction. Do I miss something or
is it really like this? Is this a known issue?

I thought that I could send my gesture events to the display interactor
to adapt the scene. But knowing about this, I think that I have to
convert my touch events into mouse events and then send them to the
QVTKQuickItem, since it is not supporting TouchEvents.

Does anyone has a better idea?

I forgot to mention above that this just happens in the 3D scene. In the
2D scenes the DisplayInteractor is working as expected, even when the
events are not passed to the qvtkwidget/quickitem.

Best

Martin