Python - VTK boxwidget rotation-handlers

Question

what I have seen so far, is that there is a widget which shows a 3D-bounding-box with 6-handles. Python Boxwidget Exampler

I would like translate the box by clicking [cntrl]+draging the handle and rotate only around the y-axis by clicking [shift]+draging the handle...

Every interaction should just only occur to the box in the scene and nothing else.

Do I have to overwrite the box-widget functions? Or which exact function should I modify. Should I add an interaction obeserver?

And somehow - the handles are getting larger in size with the first 2 or 3 interactions, did someone experience the same issue?

EDIT:

That is my current code:

                self.boxWidget = vtk.vtkBoxWidget()
                self.boxWidget.SetInteractor(self.renderWindowInteractor)
                self.boxWidget.SetProp3D(self.boxes_3d_actors[obj_cls_name][0])
                self.boxWidget.SetPlaceFactor(1.0)
                self.boxWidget.PlaceWidget()

Where self.boxes_3d_actors is an array of vtk.vtkAssembly(), which consist of polylines.

Now I need somehow to overwrite the interaction event of the handles. The best would be to create an inherited class of vtkBoxwidget with own interaction functions.

Answer 1

You have to set Interactor according to your requirement. for common pan and rotate below is the code.

#Setting Renderer
renderer = vtk.vtkRenderer()
renderer.AddActor(self.boxes_3d_actors[obj_cls_name][0])
renwin = vtk.vtkRenderWindow()
renwin.AddRenderer(renderer)

# Setting interactor
interactor = vtk.vtkRenderWindowInteractor()
interactor.SetRenderWindow(renwin)

boxWidget = vtk.vtkBoxWidget()
boxWidget.SetInteractor(interactor)
boxWidget.SetProp3D(self.boxes_3d_actors[obj_cls_name][0])
boxWidget.SetPlaceFactor(1.0)
boxWidget.PlaceWidget()

For setting the rotation and translate of object you can see the following links of documnetations: https://vtk.org/Wiki/VTK/Examples/Python/Interaction/MouseEvents https://vtk.org/doc/nightly/html/classvtkCamera.html