# Memory leak in QVTK widget and PCL visualizer
**URL:** https://discourse.vtk.org/t/memory-leak-in-qvtk-widget-and-pcl-visualizer/6881
**Category:** Development
**Created:** [October 14, 2021, 3:33am UTC](https://discourse.vtk.org/t/memory-leak-in-qvtk-widget-and-pcl-visualizer/6881 "2021-10-14T03:33:14Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@SurajJadhav](https://discourse.vtk.org/u/SurajJadhav)
#### Post date: [October 14, 2021, 3:33am UTC](https://discourse.vtk.org/t/memory-leak-in-qvtk-widget-and-pcl-visualizer/6881/1 "2021-10-14T03:33:14Z")
I m using Ubuntu 20.04 with Qt5.12 for developing a QT project which uses a QVTK widget to display a 3D PCL visualiser. I m facing memory leak issues after defining the visualiser and vtk widget relationship. The header file contents are as follows:
```auto
class SiLS : public QMainWindow
{
Q_OBJECT
public:
SiLS(QWidget *parent = nullptr);
~SiLS();
private:
Ui::SiLS *ui;
pcl::visualization::PCLVisualizer::Ptr viewer_3D;
};
```
The cpp file contents are as follows:
```auto
SiLS::SiLS(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::SiLS)
{
ui->setupUi(this);
viewer_3D.reset (new pcl::visualization::PCLVisualizer ("viewer_3D", false));
viewer_3D->setupInteractor (ui->qvtkWidget->GetInteractor (), ui->qvtkWidget->GetRenderWindow ());
ui->qvtkWidget->SetRenderWindow(viewer_3D->getRenderWindow());
}
SiLS::~SiLS()
{
delete ui;
}
```
Only these 3 lines of code in the constructor is giving lot of memory leak issues. How to destruct the qvtkwidget properly?
---
### Author:  [@jcfr](https://discourse.vtk.org/u/jcfr)
#### Post date: [October 14, 2021, 4:32am UTC](https://discourse.vtk.org/t/memory-leak-in-qvtk-widget-and-pcl-visualizer/6881/2 "2021-10-14T04:32:16Z")
Thanks for reporting the problem.
What do you exactly mean by “memory leaks” ? Are you referring to issues discovered using tool like `memcheck`, or are these reported as [vtkDebugLeaks](https://vtk.org/doc/nightly/html/classvtkDebugLeaks.html) ?
To better understand how the different objects are created, could you share a like to a minimal GitHub project allowing to reproduce the problem ? The project would include relevant source files, a `CMakeLists.txt`, a `README.md` detailing how to download and build the dependencies (VTK, pcl, …)
Looking at the snippet you shared, it is unclear how the `Ui::SiLS` object is implemented.
---
### Author:  [@SurajJadhav](https://discourse.vtk.org/u/SurajJadhav)
#### Post date: [October 14, 2021, 4:52am UTC](https://discourse.vtk.org/t/memory-leak-in-qvtk-widget-and-pcl-visualizer/6881/3 "2021-10-14T04:52:03Z")
Memory leak issues were generated by valgrind which is present in Qt Creator. I have committed the project files to Github [here](https://github.com/Surajj4837-th/SiLS). Readme file shows detailed installation setup.
---
### Author:  [@SurajJadhav](https://discourse.vtk.org/u/SurajJadhav)
#### Post date: [October 18, 2021, 10:17am UTC](https://discourse.vtk.org/t/memory-leak-in-qvtk-widget-and-pcl-visualizer/6881/4 "2021-10-18T10:17:16Z")
One of the issue trace back is as shown below:
How to debug in these lib files?