QVTKWidget Shows Transparent Plane

Hello Guys,

I try this Example to visualize the Point Cloud. But when I run the code, QVTKWidget becomes like this image. QVTKWidget is transparent and can see background desktop screen at the place of widget. I also try other examples with QVTKWidget but get the same error like the above image. Which version of VTK and Qt should be used to visualize the point cloud data? And Which type of Widget should be used?
I am using::

  • Ubuntu 18.04
  • Qt 5.9.5
  • PCL 1.8
  • Vtk 6.3

Please give me suggestions. I am just a beginner. Please answer my question. I really need your help.

Best regards.