[vtkusers] Advice on mitigating choppy resize with Qt 5 + VTK 7.1
Elvis Stansvik
elvis.stansvik at orexplore.com
Fri Jun 9 08:24:57 EDT 2017
2017-06-08 8:45 GMT+02:00 Elvis Stansvik <elvis.stansvik at orexplore.com>:
>
> Den 8 juni 2017 8:26 fm skrev "Manfred Gratt" <gratt at intales.com>:
> >
> >
> >
> > On 07/06/17 14:15, Elvis Stansvik wrote:
> >>
> >> 2017-03-13 10:37 GMT+01:00 Elvis Stansvik <elvis.stansvik at orexplore.com
> >:
> >>>
> >>> 2017-03-13 10:32 GMT+01:00 Elvis Stansvik <
> elvis.stansvik at orexplore.com>:
> >>> > 2017-03-07 16:10 GMT+01:00 Elvis Stansvik <
> elvis.stansvik at orexplore.com>:
> >>> >> 2017-03-07 15:58 GMT+01:00 Elvis Stansvik <
> elvis.stansvik at orexplore.com>:
> >>> >>> 2017-03-07 15:53 GMT+01:00 David Cole <DLRdave at aol.com>:
> >>> >>>> On Windows, we make resizing our windows interactive by getting
> the
> >>> >>>> vtkInteractorStyle associated with the render window containing
> the
> >>> >>>> volume rendering, and then calling StartState at resize begin time
> >>> >>>> (OnEnterSizeMove) and StopState at resize end time
> (OnExitSizeMove).
> >>> >>>>
> >>> >>>> I suppose there may be a Qt equivalent which works on many
> platforms
> >>> >>>> for beginning and ending a resize action. If not, there are
> definitely
> >>> >>>> platform-specific hooks you can intercept to achieve smooth
> resizing
> >>> >>>> with this technique.
> >>> >>>>
> >>> >>>> Wrapping anything in a StartState/StopState pair on the
> >>> >>>> vtkInteractorStyle will cause "interactive frame rate rendering"
> to be
> >>> >>>> in effect in between the calls. The volume rendering is not as
> nice
> >>> >>>> looking during interactions, but it is definitely speedier.
> >>> >>>
> >>> >>> Ah, I was just about to reply to myself with some further
> information:
> >>> >>>
> >>> >>> I know that during interaction, the quality of the rendering is
> >>> >>> decreased, and that this can account for some of the performance
> >>> >>> discrepancy I'm seeing between camera movement vs window resize.
> >>> >>>
> >>> >>> But, I've experimented with disabling the quality degradation
> during
> >>> >>> interactions (so that the two should be on "equal footing"), and
> the
> >>> >>> resizing is still much more choppy than when interacting with the
> >>> >>> camera. So there must be something else.
> >>> >>>
> >>> >>> In fact, in the screencast I showed, I wasn't using the volume
> >>> >>> renderer's default built-in quality degradation during interaction.
> >>> >>> I'm using my own since I've found that VTKs own is a little too
> >>> >>> aggressive in degrading the quality to maintain frame rate.
> >>> >>
> >>> >> To illustrate, look at the attached screen recording. In this test
> >>> >> case, I'm using
> >>> >>
> >>> >> mapper->AutoAdjustSampleDistancesOff();
> >>> >> mapper->SetSampleDistance(0.0002);
> >>> >>
> >>> >> on my vtkGPUVolumeRayCastMapper, to turn off the automatic
> adjustment
> >>> >> of sample distance during interactions, and hardcode the sample
> >>> >> distance to 0.0002.
> >>> >>
> >>> >> Notice how the rendering is still reasonably smooth during
> >>> >> interaction, but during resize, the rendering sometimes lags with
> 100s
> >>> >> of milliseconds. During the resizing I was getting warnings like
> >>> >>
> >>> >> Warning: In /buildbot/vtk7-builder/build/Rendering/OpenGL2/
> vtkXOpenGLRenderWindow.cxx,
> >>> >> line 1207
> >>> >> vtkXOpenGLRenderWindow (0x2a629d0): warning window did not resize in
> >>> >> the allotted time
> >>> >>
> >>> >> printed.
> >>> >
> >>> > No ideas where this discrepancy in refresh rate, despite automatic
> >>> > adjustment of sample distance being turned off, comes from?
> >>> >
> >>> > At the moment I've worked around it by simply resorting to bounding
> >>> > box rendering when my VTK windows are resized, since the choppy
> resize
> >>> > behavior was quite jarring. But that's a kludge and I'd much rather
> >>> > find the real problem :/
> >>> >
> >>> > Below is a minimal test case, and I'm attaching a video where I first
> >>> > interact with the volume rendering, giving a smooth albeit a little
> >>> > slow frame rate, and then resizing the window, which gives a jerky
> and
> >>> > choppy rendering.
> >>> >
> >>> > This was on a Thinkpad T440s laptop with Intel HD 4400 graphics. VTK
> >>> > 7.1 and Qt 5.5.1 running on Kubuntu 16.04.
> >>> >
> >>> > Elvis
> >>> >
> >>> >
> >>> > main.cpp:
> >>> >
> >>> > #include <random>
> >>> >
> >>> > #include <vtkCamera.h>
> >>> > #include <vtkColorTransferFunction.h>
> >>> > #include <vtkGPUVolumeRayCastMapper.h>
> >>> > #include <vtkImageData.h>
> >>> > #include <vtkNew.h>
> >>> > #include <vtkPiecewiseFunction.h>
> >>> > #include <vtkRenderer.h>
> >>> > #include <vtkRenderWindow.h>
> >>> > #include <vtkRenderWindowInteractor.h>
> >>> > #include <vtkVolume.h>
> >>> > #include <vtkVolumeProperty.h>
> >>> >
> >>> > int main(int argc, char *argv[])
> >>> > {
> >>> > vtkNew<vtkColorTransferFunction> colorFunction;
> >>> > colorFunction->AddRGBPoint(0.0, 0.0, 0.0, 0.0);
> >>> > colorFunction->AddRGBPoint(1.0, 0.0, 0.0, 0.0);
> >>> >
> >>> > vtkNew<vtkPiecewiseFunction> opacityFunction;
> >>> > opacityFunction->AddPoint(0.0, 0.0);
> >>> > opacityFunction->AddPoint(1.0, 0.02);
> >>> >
> >>> > vtkNew<vtkImageData> data;
> >>> > data->SetExtent(0, 250, 0, 250, 0, 500);
> >>> > data->AllocateScalars(VTK_FLOAT, 1);
> >>> > std::random_device device;
> >>> > std::mt19937 engine(device());
> >>> > std::uniform_real_distribution<> distribution(0, 1);
> >>> > auto dataPointer = static_cast<float
> *>(data->GetScalarPointer());
> >>> > for (int i = 0; i < 250*250*500; ++i) {
> >>> > *dataPointer = distribution(engine);
> >>> > ++dataPointer;
> >>> > }
> >>> >
> >>> > vtkNew<vtkGPUVolumeRayCastMapper> mapper;
> >>> > mapper->SetInputData(data.Get());
> >>>
> >>> Sorry, the test case should have had
> >>>
> >>> mapper->AutoAdjustSampleDistancesOff();
> >>> mapper->SetSampleDistance(1);
> >>>
> >>> here, to show that the discrepancy is there even when automatic
> >>> adjustment of sample distance is turned off.
> >>>
> >>> The result is the same, the rendering is keeping up much better during
> >>> interaction that it is during window resize.
> >>>
> >>> I can understand if it's a little heavier to re-render after window
> >>> resize, but not by that much, so I think something is wrong
> >>
> >>
> >> Anybody have some more advise on this? I'm seeing the same problem in
> PV 5.4.
> >>
> >> I had hoped that maybe the new QVTKOpenGLWidget would change things,
> but it hasn't. I would really like to remove the workarounds I have in
> place that degrades the rendering to bounding boxes during widget resizing.
> >>
> >> Elvis
> >
> > Hi Elvis,
> > if you are using Qt5.5 and VTK the problem may be related to this bug:
> >
> > http://vtk.1045678.n5.nabble.com/Delayed-mouse-interaction-
> due-to-event-loop-bug-in-Qt5-td5730474.html
> >
> > https://bugreports.qt.io/browse/QTBUG-40889
> >
> > I have this problem with VTK6 and VTK7 using Ubuntu 16.04 but it was
> fixed in Ubuntu 16.10
> > that has Qt5.6 which fixes the bug. Have you tried your program on a
> newer version of Ubuntu?
>
> Sorry that my thread has gotten so long, but I mentioned QTBUG-40889 in an
> earlier mail, and that's unfortunately not it. I'm well aware of that bug
> and even submitted an SRU to backport the upstream fix to 16.04 (not sure
> of the status of that).
>
> I also see the problem both with my AppImage build, which uses 5.6, and on
> macOS, where I use 5.8.
>
I just tested on Windows 7 as well (Qt 5.6, VTK 8.0.0.rc1), and if
anything, the problem is even worse than on Linux :/
Elvis
> What I would expect is that resizing a window, VTK should be able to
> maintain roughly the same framerate as during normal interaction (sample
> distance reduction turned off). But instead, each frame is seemingly taking
> a lot more time, which I think is what leads to the stuttering.
>
> The test case I sent earlier should show the problem, even on newer Qt
> versions.
>
> Elvis
>
> >
> > Manfred
> >
> >
> >
> >>
> >>>
> >>>
> >>> Elvis
> >>>
> >>> >
> >>> > vtkNew<vtkVolumeProperty> property;
> >>> > property->SetScalarOpacity(opacityFunction.Get());
> >>> > property->SetColor(colorFunction.Get());
> >>> >
> >>> > vtkNew<vtkVolume> volume;
> >>> > volume->SetMapper(mapper.Get());
> >>> > volume->SetProperty(property.Get());
> >>> >
> >>> > vtkNew<vtkRenderer> renderer;
> >>> > renderer->AddVolume(volume.Get());
> >>> > renderer->SetBackground(1.0, 1.0, 1.0);
> >>> >
> >>> > vtkNew<vtkRenderWindow> window;
> >>> > window->AddRenderer(renderer.Get());
> >>> >
> >>> > renderer->ResetCamera();
> >>> >
> >>> > vtkNew<vtkRenderWindowInteractor> interactor;
> >>> > interactor->SetRenderWindow(window.Get());
> >>> > interactor->Start();
> >>> >
> >>> > return 0;
> >>> > }
> >>> >
> >>> >
> >>> > CMakeLists.txt:
> >>> >
> >>> > cmake_minimum_required(VERSION 3.1)
> >>> >
> >>> > project(TestCase)
> >>> >
> >>> > set(CMAKE_PREFIX_PATH ${CMAKE_PREFIX_PATH} /opt/VTK7)
> >>> >
> >>> > find_package(VTK 7.1 COMPONENTS
> >>> > vtkCommonCore
> >>> > vtkCommonDataModel
> >>> > vtkCommonExecutionModel
> >>> > vtkCommonMath
> >>> > vtkInteractionStyle
> >>> > vtkRenderingCore
> >>> > vtkRenderingOpenGL2
> >>> > vtkRenderingVolume
> >>> > vtkRenderingVolumeOpenGL2
> >>> > REQUIRED
> >>> > )
> >>> >
> >>> > add_executable(TestCase WIN32 main.cpp)
> >>> >
> >>> > target_link_libraries(TestCase PUBLIC
> >>> > vtkCommonCore
> >>> > vtkCommonDataModel
> >>> > vtkCommonExecutionModel
> >>> > vtkCommonMath
> >>> > vtkInteractionStyle
> >>> > vtkRenderingCore
> >>> > vtkRenderingOpenGL2
> >>> > vtkRenderingVolume
> >>> > vtkRenderingVolumeOpenGL2
> >>> > )
> >>> >
> >>> > target_include_directories(TestCase PUBLIC
> >>> > ${VTK_INCLUDE_DIRS}
> >>> > )
> >>> >
> >>> > target_compile_definitions(TestCase PUBLIC
> >>> > ${VTK_DEFINITIONS}
> >>> > )
> >>> >
> >>> > set_target_properties(TestCase PROPERTIES
> >>> > CXX_STANDARD 14
> >>> > CXX_STANDARD_REQUIRED ON
> >>> > )
> >>> >
> >>> >>
> >>> >> Elvis
> >>> >>
> >>> >>>
> >>> >>> Elvis
> >>> >>>
> >>> >>>>
> >>> >>>>
> >>> >>>> HTH,
> >>> >>>> David C.
> >>> >>>>
> >>> >>>>
> >>> >>>>
> >>> >>>> On Tue, Mar 7, 2017 at 9:33 AM, Elvis Stansvik
> >>> >>>> <elvis.stansvik at orexplore.com> wrote:
> >>> >>>>> 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
> >>> >>>>> _______________________________________________
> >>> >>>>> Powered by www.kitware.com
> >>> >>>>>
> >>> >>>>> Visit other Kitware open-source projects at
> http://www.kitware.com/opensource/opensource.html
> >>> >>>>>
> >>> >>>>> Please keep messages on-topic and check the VTK FAQ at:
> http://www.vtk.org/Wiki/VTK_FAQ
> >>> >>>>>
> >>> >>>>> Search the list archives at: http://markmail.org/search/?q=
> vtkusers
> >>> >>>>>
> >>> >>>>> Follow this link to subscribe/unsubscribe:
> >>> >>>>> http://public.kitware.com/mailman/listinfo/vtkusers
> >>
> >>
> >>
> >>
> >> _______________________________________________ Powered by
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> >
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> >
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> >
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> >
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