Thanks. We are trying to manage that. We found a project in github which works in vtk8 but not in vtk9.
The project works fine with vtk8 in rendering but has some flaw in GPU volume rendering and interaction. So now we are usingVTK8.2 + QT5.15, and we use vtk9 as a programming reference for interaction.
Currently it seems to work fine, but we haven’t test it much.
Hope it helps.