message: MPI does not need frame cancel on frameOps change.  That bug has been fixed.
  Fixed after OSPRay 2.5.0 release
diff: @@ -147,19 +147,6 @@ void Frame::refreshFrameOperations()
  auto denoiserEnabled = navMode ? denoiseNavFB : denoiseFB;
  auto toneMapperEnabled = navMode ? toneMapNavFB : toneMapFB;
  - // If frameOps change, cancel and wait on current frame before making
  - // framebuffer changes
  - static auto currentDenoiser = false;
  - static auto currentToneMapper = false;
  - if (currentDenoiser != denoiserEnabled
  - || currentToneMapper != toneMapperEnabled) {
  - cancelFrame();
  - waitOnFrame();
  - resetAccumulation();
  - }
  - currentDenoiser = denoiserEnabled;
  - currentToneMapper = toneMapperEnabled;
  -
  fb.updateDenoiser(denoiserEnabled);
  fb.updateToneMapper(toneMapperEnabled);
  fb.updateImageOperations();
  