SaveScreenshot in pvpython/pvbatch takes significantly longer than GUI when StreamTracer is used

I have a large amount of CFD results that I want to save images of. There are two types of images: surface pressures alone and surface pressures with streamlines (created with Calculator and StreamTracer). When I use pvpython/pvbatch with a script to save a screenshot, the streamline images take significantly longer to save than the non-streamline images (about 6 minutes vs about 5 seconds). Weirdly this is even slower than if I would go into the Paraview GUI, load the state, then save a screenshot manually (takes probably 1 minute from opening the GUI to saved image).

I’ve played around with the different SaveScreenshot options but have had no luck in shortening the amount of time it takes. Here’s a the macro I’m using to save.

NOTE: I’m positive the difference is solely due to the SaveScreenshot command. If I remove the SaveScreenshot command there is barely any time difference between rendering views with/without streamlines.


from paraview.simple import *
#### disable automatic camera reset on 'Show'
paraview.simple._DisableFirstRenderCameraReset()

# load state
LoadState('STATE_FILE', DataDirectory='CFD_DATA')

# find view
renderView1 = FindViewOrCreate('RenderView1', viewtype='RenderView')

# set active view
SetActiveView(renderView1)

# save screenshot
SaveScreenshot('PICSAVEPICNAME.png', renderView1, ImageResolution=[1280, 960],
    TransparentBackground=1)