[vtkusers] QVTKWidget slow rendering

[Daniele Giunchi]

Hi,
The build configuration is equal.
We check all the difference and we notice that the only difference was
immediate mode rendering
enabled i  the slower sample. Putting false , resolve the problem.
Reading the documentation, I think that it's a contradiction call a
boolean variable ImmediateRendering when, if true,
the rendering can be slower :)

thank you very much,
cheers

Daniele


On Fri, Jun 10, 2011 at 8:06 PM, Clinton Stimpson <clinton at elemtech.com> wrote:
> On Friday, June 10, 2011 08:58:27 am Daniele Giunchi wrote:
>> Dear All,
>> I try some example in VTK-5.6 compiled with VS2008 on WIndows XP,
>> using Qt-4.7.2.
>> In particular I tested a vtk Structured Points (~50 Mb) in two
>> different examples, using basically this code:
>>
>> ---------------------------------------------------------------------------
>> ---------------- /Load dataSet
>>  vtkDataSetReader *reader = vtkDataSetReader::New();
>>  reader->SetFileName("vtkTestVolume.vtk");
>>  reader->Update();
>>
>>  vtkContourFilter* cf = vtkContourFilter::New();
>>  cf->UseScalarTreeOn();
>>  cf->SetInputConnection(reader->GetOutputPort());
>>  cf->SetNumberOfContours(1);
>>  cf->SetValue(0, 30000);
>>
>>  // Mapper
>>  VTK_CREATE(vtkPolyDataMapper, mapper);
>>  mapper->ImmediateModeRenderingOn();
>>  mapper->SetInputConnection(cf->GetOutputPort());
>> ---------------------------------------------------------------------------
>> ---
>>
>> and the two examples are:
>>
>> 1) Cone5.cxx (direct opengl rendering)
>> 2) SimpleView.cxx (using QVTKWidget rendering)
>>
>> The same data, on first example render with an acceptable frame rate,
>> while the second is incredibly slow.
>> Using the widget also in our test application, we notice the same latency.
>> Have you got any suggestion for this ?
>
> So all other parameters are equal?  You're not compare a debug build with a
> release build?
>
> Is it also a problem if you modify Cone5.cxx to use a QVTKWidget similar to
> VTK/Examples/GUI/Qt/ImageViewer.main.cxx?
>
> --
> Clinton Stimpson
> Elemental Technologies, Inc
> Computational Simulation Software, LLC
> www.csimsoft.com
>