[vtkusers] Advice on mitigating choppy resize with Qt 5 + VTK 7.1

[Elvis Stansvik]

2017-03-07 15:17 GMT+01:00 Elvis Stansvik <elvis.stansvik at orexplore.com>:
> Hi all,
>
> I'm using Qt 5.5.1 and VTK 7.1. The program has a couple of VTKWidget
> showing volume renderings, as well as a window with a chart.

Actually, I'm able to reproduce this behavior when not using Qt at
all, but just a regular render window + interactor setup with a single
volume rendered. Camera interaction is nice and fast, but resizing the
window, the rendering is very choppy. I'm also getting

Warning: In /buildbot/vtk7-builder/build/Rendering/OpenGL2/vtkXOpenGLRenderWindow.cxx,
line 1207
vtkXOpenGLRenderWindow (0x1353a10): warning window did not resize in
the allotted time

printed to the console, so it seems VTK detects what I'm seeing
visually. I did not get this warning printed in the Qt + VTK app.

Elvis

>
> Have a look at the attached screen recording. Notice how camera
> interaction in both VTK render windows is nice and smooth, but when
> resizing the windows, the updating of the renderings is very
> slow/choppy.
>
> I've been trying to debug this, or at least finding a way of
> mitigating it. Could it be that Qt is delivering too many resize
> events? Has anyone else dealt with this problem?
>
> Thanks in advance for any advice,
> Elvis