MITK supports rendering with both openGL and VTK. However, VTK does ensure a "clean" (or regular) openGL context after rendering. It takes some effort to ensure a clean openGL context after VTK rendering.
Today, in the weekly MITK meeting we decided to try to wrap our openGL mappers with the VTK mapper concept. This will result in a unified mapping concept for MITK/VTK and we can get rid of switching between different contexts.
I will make a list of the MITK openGL mappers to wrap and try to figure out which openGL policy/guideline VTK uses for coding new mappers.