I have a qt5.12 application with vtk8.2 which uses QVTKWidget. Now I want to use vtk9.1 instead of vtk8.2. But vtk9.1 does not support QVTKWidget anymore. So, I just changed it into QVTKOpenGLNativeWidget and did not do anything more. I even compiled it (VS2015 update 3), but this application fails on the module "vtkFixedPointVolumeRayCastMapper.cxx" on the lines
this->ImageDisplayHelper = vtkRayCastImageDisplayHelper::New(); // 1
this->ImageDisplayHelper->PreMultipliedColorsOn(); // 2
because this->ImageDisplayHelper is nullptr after //1. As far as I understood this is because "vtkRayCastImageDisplayHelper" is not registered.
So, how can I register it? Maybe, I'm completely wrong and should migrate to vtk9.1 in some another way?