example's input data not found.

Hi, everyone.
when I try to run exampe “./Examples/GUI/Qt/FourPaneViewer” failed
I know I need a dicom file , but I can not find a dcm file in the src-dir, will anyone give me a suggestion? thanks.

2021-08-06 16:24:33.274 (   0.329s) [        6C6AF7C0]vtkDICOMImageReader.cxx:144    ERR| vtkDICOMImageReader (0x55687f39de10): Couldn't open /home/eton/opt/vtks/vtk-src/build/ExternalData/GUISupport/QtQuick/Testing/Data/Baseline/TestQQuickVTKRenderWindow.png
2021-08-06 16:24:33.274 (   0.329s) [        6C6AF7C0]vtkDICOMImageReader.cxx:237    ERR| vtkDICOMImageReader (0x55687f39de10): Either a filename was not specified or the specified directory does not contain any DICOM images.
2021-08-06 16:24:33.274 (   0.329s) [        6C6AF7C0]       vtkExecutive.cxx:752    ERR| vtkCompositeDataPipeline (0x55687f259200): Algorithm vtkDICOMImageReader(0x55687f39de10) returned failure for request: vtkInformation (0x55687f493eb0)
  Debug: Off
  Modified Time: 4334
  Reference Count: 1
  Registered Events: (none)

You probably need to build the ExternalData target for VTK (called VTKData) to get it.

so sorry about I am know too little about it. what you try to tell me is use another build command to build? because in my build directory already had a lot data in ./build/ExternalData also has some dicom file but when I use the dicom directory as parameter to it. it tell me not the right dicom file.

Yes, it is make VTKData.

@ben.boeckel sorry to disturb again. but after a run the command, there’s no expected file generated. the dcm file I find already in there.
Below is the log info.

eton@9u:~/opt/vtks/vtk-src/build$  make VTKData
[100%] Built target VTKData
eton@9u:~/opt/vtks/vtk-src/build$ find ./ -name "*.dcm"

Hi, everyone, based on the talk above, I think May be what I need most is a reference, but do not found it.
Are there any reference documents on examples and usage data? I didn’t find a valid reference in VTK examples.

How are you running the example?

the cli I use is:

~/opt/vtks/vtk-src/Examples/GUI/Qt/build-FourPaneViewer-Desktop_Qt_5_15_2_GCC_64bit-Debug/QtVTKRenderWindows ~/opt/vtks/vtk-src/build/ExternalData/Testing/Data/dicom/collection/

Hmm. I don’t know. That looks right to me, but maybe something is up with the reader not finding the files for some reason?

@ben.boeckel will you please take a screenshot about the program running result. and the ls result about
based on what you have and I will know what the example should be;
Because you take out the running results of your program, I can take your results as a basic standard, so that I can further judge where I should continue to deal with it.