<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">2017-03-13 10:37 GMT+01:00 Elvis Stansvik <span dir="ltr"><<a href="mailto:elvis.stansvik@orexplore.com" target="_blank">elvis.stansvik@orexplore.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="HOEnZb"><div class="h5">2017-03-13 10:32 GMT+01:00 Elvis Stansvik <<a href="mailto:elvis.stansvik@orexplore.com">elvis.stansvik@orexplore.com</a>><wbr>:<br>
> 2017-03-07 16:10 GMT+01:00 Elvis Stansvik <<a href="mailto:elvis.stansvik@orexplore.com">elvis.stansvik@orexplore.com</a>><wbr>:<br>
>> 2017-03-07 15:58 GMT+01:00 Elvis Stansvik <<a href="mailto:elvis.stansvik@orexplore.com">elvis.stansvik@orexplore.com</a>><wbr>:<br>
>>> 2017-03-07 15:53 GMT+01:00 David Cole <<a href="mailto:DLRdave@aol.com">DLRdave@aol.com</a>>:<br>
>>>> On Windows, we make resizing our windows interactive by getting the<br>
>>>> vtkInteractorStyle associated with the render window containing the<br>
>>>> volume rendering, and then calling StartState at resize begin time<br>
>>>> (OnEnterSizeMove) and StopState at resize end time (OnExitSizeMove).<br>
>>>><br>
>>>> I suppose there may be a Qt equivalent which works on many platforms<br>
>>>> for beginning and ending a resize action. If not, there are definitely<br>
>>>> platform-specific hooks you can intercept to achieve smooth resizing<br>
>>>> with this technique.<br>
>>>><br>
>>>> Wrapping anything in a StartState/StopState pair on the<br>
>>>> vtkInteractorStyle will cause "interactive frame rate rendering" to be<br>
>>>> in effect in between the calls. The volume rendering is not as nice<br>
>>>> looking during interactions, but it is definitely speedier.<br>
>>><br>
>>> Ah, I was just about to reply to myself with some further information:<br>
>>><br>
>>> I know that during interaction, the quality of the rendering is<br>
>>> decreased, and that this can account for some of the performance<br>
>>> discrepancy I'm seeing between camera movement vs window resize.<br>
>>><br>
>>> But, I've experimented with disabling the quality degradation during<br>
>>> interactions (so that the two should be on "equal footing"), and the<br>
>>> resizing is still much more choppy than when interacting with the<br>
>>> camera. So there must be something else.<br>
>>><br>
>>> In fact, in the screencast I showed, I wasn't using the volume<br>
>>> renderer's default built-in quality degradation during interaction.<br>
>>> I'm using my own since I've found that VTKs own is a little too<br>
>>> aggressive in degrading the quality to maintain frame rate.<br>
>><br>
>> To illustrate, look at the attached screen recording. In this test<br>
>> case, I'm using<br>
>><br>
>> mapper-><wbr>AutoAdjustSampleDistancesOff()<wbr>;<br>
>> mapper->SetSampleDistance(0.<wbr>0002);<br>
>><br>
>> on my vtkGPUVolumeRayCastMapper, to turn off the automatic adjustment<br>
>> of sample distance during interactions, and hardcode the sample<br>
>> distance to 0.0002.<br>
>><br>
>> Notice how the rendering is still reasonably smooth during<br>
>> interaction, but during resize, the rendering sometimes lags with 100s<br>
>> of milliseconds. During the resizing I was getting warnings like<br>
>><br>
>> Warning: In /buildbot/vtk7-builder/build/<wbr>Rendering/OpenGL2/<wbr>vtkXOpenGLRenderWindow.cxx,<br>
>> line 1207<br>
>> vtkXOpenGLRenderWindow (0x2a629d0): warning window did not resize in<br>
>> the allotted time<br>
>><br>
>> printed.<br>
><br>
> No ideas where this discrepancy in refresh rate, despite automatic<br>
> adjustment of sample distance being turned off, comes from?<br>
><br>
> At the moment I've worked around it by simply resorting to bounding<br>
> box rendering when my VTK windows are resized, since the choppy resize<br>
> behavior was quite jarring. But that's a kludge and I'd much rather<br>
> find the real problem :/<br>
><br>
> Below is a minimal test case, and I'm attaching a video where I first<br>
> interact with the volume rendering, giving a smooth albeit a little<br>
> slow frame rate, and then resizing the window, which gives a jerky and<br>
> choppy rendering.<br>
><br>
> This was on a Thinkpad T440s laptop with Intel HD 4400 graphics. VTK<br>
> 7.1 and Qt 5.5.1 running on Kubuntu 16.04.<br>
><br>
> Elvis<br>
><br>
><br>
> main.cpp:<br>
><br>
> #include <random><br>
><br>
> #include <vtkCamera.h><br>
> #include <vtkColorTransferFunction.h><br>
> #include <vtkGPUVolumeRayCastMapper.h><br>
> #include <vtkImageData.h><br>
> #include <vtkNew.h><br>
> #include <vtkPiecewiseFunction.h><br>
> #include <vtkRenderer.h><br>
> #include <vtkRenderWindow.h><br>
> #include <vtkRenderWindowInteractor.h><br>
> #include <vtkVolume.h><br>
> #include <vtkVolumeProperty.h><br>
><br>
> int main(int argc, char *argv[])<br>
> {<br>
> vtkNew<<wbr>vtkColorTransferFunction> colorFunction;<br>
> colorFunction->AddRGBPoint(0.<wbr>0, 0.0, 0.0, 0.0);<br>
> colorFunction->AddRGBPoint(1.<wbr>0, 0.0, 0.0, 0.0);<br>
><br>
> vtkNew<vtkPiecewiseFunction> opacityFunction;<br>
> opacityFunction->AddPoint(0.0, 0.0);<br>
> opacityFunction->AddPoint(1.0, 0.02);<br>
><br>
> vtkNew<vtkImageData> data;<br>
> data->SetExtent(0, 250, 0, 250, 0, 500);<br>
> data->AllocateScalars(VTK_<wbr>FLOAT, 1);<br>
> std::random_device device;<br>
> std::mt19937 engine(device());<br>
> std::uniform_real_<wbr>distribution<> distribution(0, 1);<br>
> auto dataPointer = static_cast<float *>(data->GetScalarPointer());<br>
> for (int i = 0; i < 250*250*500; ++i) {<br>
> *dataPointer = distribution(engine);<br>
> ++dataPointer;<br>
> }<br>
><br>
> vtkNew<<wbr>vtkGPUVolumeRayCastMapper> mapper;<br>
> mapper->SetInputData(data.Get(<wbr>));<br>
<br>
</div></div>Sorry, the test case should have had<br>
<br>
mapper-><wbr>AutoAdjustSampleDistancesOff()<wbr>;<br>
mapper->SetSampleDistance(1);<br>
<br>
here, to show that the discrepancy is there even when automatic<br>
adjustment of sample distance is turned off.<br>
<br>
The result is the same, the rendering is keeping up much better during<br>
interaction that it is during window resize.<br>
<br>
I can understand if it's a little heavier to re-render after window<br>
resize, but not by that much, so I think something is wrong<br></blockquote><div><br></div><div>Anybody have some more advise on this? I'm seeing the same problem in PV 5.4.<br><br></div><div>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.<br><br></div><div>Elvis<br> <br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<span class="HOEnZb"><font color="#888888"><br>
Elvis<br>
</font></span><div class="HOEnZb"><div class="h5"><br>
><br>
> vtkNew<vtkVolumeProperty> property;<br>
> property->SetScalarOpacity(<wbr>opacityFunction.Get());<br>
> property->SetColor(<wbr>colorFunction.Get());<br>
><br>
> vtkNew<vtkVolume> volume;<br>
> volume->SetMapper(mapper.Get()<wbr>);<br>
> volume->SetProperty(property.<wbr>Get());<br>
><br>
> vtkNew<vtkRenderer> renderer;<br>
> renderer->AddVolume(volume.<wbr>Get());<br>
> renderer->SetBackground(1.0, 1.0, 1.0);<br>
><br>
> vtkNew<vtkRenderWindow> window;<br>
> window->AddRenderer(renderer.<wbr>Get());<br>
><br>
> renderer->ResetCamera();<br>
><br>
> vtkNew<<wbr>vtkRenderWindowInteractor> interactor;<br>
> interactor->SetRenderWindow(<wbr>window.Get());<br>
> interactor->Start();<br>
><br>
> return 0;<br>
> }<br>
><br>
><br>
> CMakeLists.txt:<br>
><br>
> cmake_minimum_required(VERSION 3.1)<br>
><br>
> project(TestCase)<br>
><br>
> set(CMAKE_PREFIX_PATH ${CMAKE_PREFIX_PATH} /opt/VTK7)<br>
><br>
> find_package(VTK 7.1 COMPONENTS<br>
> vtkCommonCore<br>
> vtkCommonDataModel<br>
> vtkCommonExecutionModel<br>
> vtkCommonMath<br>
> vtkInteractionStyle<br>
> vtkRenderingCore<br>
> vtkRenderingOpenGL2<br>
> vtkRenderingVolume<br>
> vtkRenderingVolumeOpenGL2<br>
> REQUIRED<br>
> )<br>
><br>
> add_executable(TestCase WIN32 main.cpp)<br>
><br>
> target_link_libraries(TestCase PUBLIC<br>
> vtkCommonCore<br>
> vtkCommonDataModel<br>
> vtkCommonExecutionModel<br>
> vtkCommonMath<br>
> vtkInteractionStyle<br>
> vtkRenderingCore<br>
> vtkRenderingOpenGL2<br>
> vtkRenderingVolume<br>
> vtkRenderingVolumeOpenGL2<br>
> )<br>
><br>
> target_include_directories(<wbr>TestCase PUBLIC<br>
> ${VTK_INCLUDE_DIRS}<br>
> )<br>
><br>
> target_compile_definitions(<wbr>TestCase PUBLIC<br>
> ${VTK_DEFINITIONS}<br>
> )<br>
><br>
> set_target_properties(TestCase PROPERTIES<br>
> CXX_STANDARD 14<br>
> CXX_STANDARD_REQUIRED ON<br>
> )<br>
><br>
>><br>
>> Elvis<br>
>><br>
>>><br>
>>> Elvis<br>
>>><br>
>>>><br>
>>>><br>
>>>> HTH,<br>
>>>> David C.<br>
>>>><br>
>>>><br>
>>>><br>
>>>> On Tue, Mar 7, 2017 at 9:33 AM, Elvis Stansvik<br>
>>>> <<a href="mailto:elvis.stansvik@orexplore.com">elvis.stansvik@orexplore.com</a>> wrote:<br>
>>>>> 2017-03-07 15:17 GMT+01:00 Elvis Stansvik <<a href="mailto:elvis.stansvik@orexplore.com">elvis.stansvik@orexplore.com</a>><wbr>:<br>
>>>>>> Hi all,<br>
>>>>>><br>
>>>>>> I'm using Qt 5.5.1 and VTK 7.1. The program has a couple of VTKWidget<br>
>>>>>> showing volume renderings, as well as a window with a chart.<br>
>>>>><br>
>>>>> Actually, I'm able to reproduce this behavior when not using Qt at<br>
>>>>> all, but just a regular render window + interactor setup with a single<br>
>>>>> volume rendered. Camera interaction is nice and fast, but resizing the<br>
>>>>> window, the rendering is very choppy. I'm also getting<br>
>>>>><br>
>>>>> Warning: In /buildbot/vtk7-builder/build/<wbr>Rendering/OpenGL2/<wbr>vtkXOpenGLRenderWindow.cxx,<br>
>>>>> line 1207<br>
>>>>> vtkXOpenGLRenderWindow (0x1353a10): warning window did not resize in<br>
>>>>> the allotted time<br>
>>>>><br>
>>>>> printed to the console, so it seems VTK detects what I'm seeing<br>
>>>>> visually. I did not get this warning printed in the Qt + VTK app.<br>
>>>>><br>
>>>>> Elvis<br>
>>>>><br>
>>>>>><br>
>>>>>> Have a look at the attached screen recording. Notice how camera<br>
>>>>>> interaction in both VTK render windows is nice and smooth, but when<br>
>>>>>> resizing the windows, the updating of the renderings is very<br>
>>>>>> slow/choppy.<br>
>>>>>><br>
>>>>>> I've been trying to debug this, or at least finding a way of<br>
>>>>>> mitigating it. Could it be that Qt is delivering too many resize<br>
>>>>>> events? Has anyone else dealt with this problem?<br>
>>>>>><br>
>>>>>> Thanks in advance for any advice,<br>
>>>>>> Elvis<br>
>>>>> ______________________________<wbr>_________________<br>
>>>>> Powered by <a href="http://www.kitware.com" rel="noreferrer" target="_blank">www.kitware.com</a><br>
>>>>><br>
>>>>> Visit other Kitware open-source projects at <a href="http://www.kitware.com/opensource/opensource.html" rel="noreferrer" target="_blank">http://www.kitware.com/<wbr>opensource/opensource.html</a><br>
>>>>><br>
>>>>> Please keep messages on-topic and check the VTK FAQ at: <a href="http://www.vtk.org/Wiki/VTK_FAQ" rel="noreferrer" target="_blank">http://www.vtk.org/Wiki/VTK_<wbr>FAQ</a><br>
>>>>><br>
>>>>> Search the list archives at: <a href="http://markmail.org/search/?q=vtkusers" rel="noreferrer" target="_blank">http://markmail.org/search/?q=<wbr>vtkusers</a><br>
>>>>><br>
>>>>> Follow this link to subscribe/unsubscribe:<br>
>>>>> <a href="http://public.kitware.com/mailman/listinfo/vtkusers" rel="noreferrer" target="_blank">http://public.kitware.com/<wbr>mailman/listinfo/vtkusers</a><br>
</div></div></blockquote></div><br></div></div>