Hi,
You can increment and decrement using the arrows. Do you mean you would want a live feedback from the 3d view behind each time a parameter is changed without having to close the dialog?
The best would be to add 3D interactive markers (like in CloudCompare) to rotate or translate with the mouse directly in the 3D view. I am not used to do that kind of stuff, but I think it is possible with the right VTK interactor:
https://lorensen.github.io/VTKExamples/site/Cxx/Interaction/MoveAGlyph/cheers,
Mathieu