Can NOT close PCLVisualizer

[lihk11]

Can NOT close PCLVisualizer

As a thread on Stackoverflow said,

" I am writing a program to record and store pointclouds. Part of the programs function to observe the recorded clouds, for this I use the PCL visualizer. The problem is that if I close the visualizers window the window just stops, but won't close. I tried calling the close() method, but nothing. I read that this was a problem before VTK 8.0, but I use 8.1 and the problem is still there. I also use PCL 1.9.1 and Ubuntu 18.04. Anyone has a solution for this? Thanks in advance. "

And I am experiencing the very same problem, could someone give some workarounds?

Code to reproduce the problem:

#include <pcl/visualization/pcl_visualizer.h>

#include <iostream>

int main(void) {
    pcl::visualization::PCLVisualizer viewer;
    while (!viewer.wasStopped()) {
        viewer.spinOnce();
    }
    viewer.close();
    std::cout << "closed!" << std::endl;
    while (true) {
    }
}

OS: Ubuntu 18.04
gcc:(Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0
VTK: 8.2.0
pcl: 1.9.1 or 1.10.1

[SergioRAgostinho]

It originally sounded like a duplicate of #172 but with the VTK version you're using, you should no longer have that problem. :/

[lihk11]

@SergioRAgostinho I have investigated #172 , and tried every solution that issue mentioned, but my problem still unsolved...
According to the last comment given by @Kaju-Bubanja the problem still exists...

[lihk11]

And I am pretty sure that the pcl library has been linked to VTK 8.2.0
the ldd output of libpcl_visualization.so

→ ldd libpcl_visualization.so
	linux-vdso.so.1 (0x00007fff46fcf000)
	libboost_filesystem.so.1.71.0 => /usr/local/lib/libboost_filesystem.so.1.71.0 (0x00007f7e67a2e000)
	libboost_thread.so.1.71.0 => /usr/local/lib/libboost_thread.so.1.71.0 (0x00007f7e6780a000)
	libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f7e675eb000)
	libpcl_io.so.1.9 => /usr/local/lib/libpcl_io.so.1.9 (0x00007f7e67265000)
	libpcl_kdtree.so.1.9 => /usr/local/lib/libpcl_kdtree.so.1.9 (0x00007f7e66f2f000)
	libvtkIOPLY-8.2.so.1 => /usr/local/lib/libvtkIOPLY-8.2.so.1 (0x00007f7e66d16000)
	libvtkRenderingContextOpenGL2-8.2.so.1 => /usr/local/lib/libvtkRenderingContextOpenGL2-8.2.so.1 (0x00007f7e66ae5000)
	libvtkRenderingLOD-8.2.so.1 => /usr/local/lib/libvtkRenderingLOD-8.2.so.1 (0x00007f7e668d6000)
	libvtkViewsContext2D-8.2.so.1 => /usr/local/lib/libvtkViewsContext2D-8.2.so.1 (0x00007f7e666ca000)
	libvtkRenderingGL2PSOpenGL2-8.2.so.1 => /usr/local/lib/libvtkRenderingGL2PSOpenGL2-8.2.so.1 (0x00007f7e664b8000)
	libvtkRenderingOpenGL2-8.2.so.1 => /usr/local/lib/libvtkRenderingOpenGL2-8.2.so.1 (0x00007f7e66086000)
	libvtkChartsCore-8.2.so.1 => /usr/local/lib/libvtkChartsCore-8.2.so.1 (0x00007f7e65cce000)
	libvtkRenderingContext2D-8.2.so.1 => /usr/local/lib/libvtkRenderingContext2D-8.2.so.1 (0x00007f7e65a8c000)
	libvtkInteractionWidgets-8.2.so.1 => /usr/local/lib/libvtkInteractionWidgets-8.2.so.1 (0x00007f7e655f5000)
	libvtkImagingSources-8.2.so.1 => /usr/local/lib/libvtkImagingSources-8.2.so.1 (0x00007f7e653a3000)
	libvtkFiltersModeling-8.2.so.1 => /usr/local/lib/libvtkFiltersModeling-8.2.so.1 (0x00007f7e65111000)
	libvtkIOImage-8.2.so.1 => /usr/local/lib/libvtkIOImage-8.2.so.1 (0x00007f7e64d80000)
	libvtkInteractionStyle-8.2.so.1 => /usr/local/lib/libvtkInteractionStyle-8.2.so.1 (0x00007f7e64b2f000)
	libvtkFiltersExtraction-8.2.so.1 => /usr/local/lib/libvtkFiltersExtraction-8.2.so.1 (0x00007f7e6482f000)
	libvtkRenderingAnnotation-8.2.so.1 => /usr/local/lib/libvtkRenderingAnnotation-8.2.so.1 (0x00007f7e6450a000)
	libvtkImagingCore-8.2.so.1 => /usr/local/lib/libvtkImagingCore-8.2.so.1 (0x00007f7e6409c000)
	libvtkRenderingFreeType-8.2.so.1 => /usr/local/lib/libvtkRenderingFreeType-8.2.so.1 (0x00007f7e63df1000)
	libvtkRenderingCore-8.2.so.1 => /usr/local/lib/libvtkRenderingCore-8.2.so.1 (0x00007f7e639e1000)
	libvtkCommonColor-8.2.so.1 => /usr/local/lib/libvtkCommonColor-8.2.so.1 (0x00007f7e637c3000)
	libvtkFiltersSources-8.2.so.1 => /usr/local/lib/libvtkFiltersSources-8.2.so.1 (0x00007f7e6351a000)
	libvtkFiltersGeneral-8.2.so.1 => /usr/local/lib/libvtkFiltersGeneral-8.2.so.1 (0x00007f7e62fe8000)
	libvtkFiltersCore-8.2.so.1 => /usr/local/lib/libvtkFiltersCore-8.2.so.1 (0x00007f7e6285c000)
        ...

[lihk11]

Any updates?

[yifan-hou]

@lihk11 I had the same problem with pcl 1.11 and vtk 8.2. It turns out the problem is caused by the immediate pause (the while loop) after viewer.close().

#include <pcl/visualization/pcl_visualizer.h>

#include <iostream>

int main(void) {
    pcl::visualization::PCLVisualizer viewer1("viewer1");
    while (!viewer1.wasStopped()) {
        viewer1.spinOnce();
    }
    viewer1.close();
    while (true) {} // if you remove this line, the close will be successful

    pcl::visualization::PCLVisualizer viewer2("viewer2");
    // now you can see two viewer windows. However,
    // if you comment out the while(true) line,
    // there should be only one window now.
    while (!viewer2.wasStopped()) {
        viewer2.spinOnce();
    }
    viewer2.close();
}

Beside while(true){}, a getchar() can also cause the same problem. It seems like the visualizer needs a flushing mechanism, something like viewer.flush().

[lihk11]

I don't think the problem is caused by inmmediate pause. A window will always remain before the whole program exits.
It looks like after calling "viewer.close()", PCL or VTK does not release those window-related resources before the corresponding thread ends.
Besides, I gave up using PCL, but wrote an osg based viewer for visualizing point clouds.

[yifan-hou]

I see, that's a slightly different problem. I don't know if the last window will stay till the program exits.

My case is that I need to draw and inspect different things in a loop; after 100 loops, I would end up with 99 dead windows.... So I basically can not do large loops. Now this problem is fixed, the window in each loop can close before the next loop starts.