[vtkusers] VTK runtime behavior: Revert to OpenGL if OpenGL2 is not supported?

[Sophonet]

Hi list,

my VTK 7.1.0 application works nicely with the OpenGL2 backend - 
however, if I use windows remote desktop, it does not start correctly, 
since remote desktop only supports OpenGL1.1 (which is well known and 
has been discussed in this list).

would it be possible somehow during runtime to (automatically / 
manually) revert to the OpenGL if OpenGL2 is not available? As far as I 
recall, one has to specify either OpenGL or OpenGL2 as backend in CMake, 
so make the choice at configuration/compile time (instead of runtime).

Best,

     sophonet