Difficulty animating a time-aware reader with an OSPRayPass

Support
#1

I have a Python program displaying data from a time-aware reader. I can play my animation without any problem.

Now, if I add an OSPRayPass, my time-aware reader responds to timestep update requests, but my render window never updates. I have tried with another supported reader, the vtkVASPAnimationReader(), re-using the test provided. The same happens. There is no rendering updates. In summary, for the two time-aware readers I have tried, the following loop plays a nice animation if using a normal OpenGL loop,

for t in timerange:
  reader.UpdateTimeStep(t)
  renWin.Render()

whereas if using an OSPRayPass, my render window never shows any new data and updates.

Yet, ParaView does it right. There must be a trick ParaView does. What am I missing in a pure VTK program?

#2

can you try calling that UpdateTimeStep on the mapper instead of the reader?

#3

Thanks for your reply. So far, the only solution I have found is to call Modified() on the mapper itself. So my loop is the following and the OSPRay renderer shows data being updated.

for t in timerange:
  reader.UpdateTimeStep(t)
  molmapper.Modified()
  renWin.Render()