ea2b217f vtkSynchronizedRenderers: capture just 1 image.
a6b03489 vtkSynchronizedRenderers: add ability to fix colored background
4ee8db5b Revert "fix blend function to avoid blending background"

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Ken Martin <ken.martin@kitware.com>
Merge-request: !5652