I can’t trace some parameter changes in StreamTracer Filter, when I change the center of Point Source.
I feel a little weird. Is a bug or some founction tracer still in development?
Hey, welcome @Chenxing_Li
In my experience I’ve found there to be some operations that the Python trace doesn’t capture, and by extension the Python-based state files (I believe they just use the trace function).
I’m not sure if there is active development on the tracing capabilities, but I would certainly hope so.
(Hey developers! 
)
The lack of parity between Python (.py) and XML (.pvsm) state files can be pretty frustrating, in my opinion.
Python tracing and state files rely on inserting code that tells what code should be generated. As ParaView is a large application, there are unfortunately some gaps in tracing completeness. Over the years, these gaps have decreased as we make sure to add Python tracing code as new code is added to ParaView. It isn’t perfect, as you have discovered, so reports like these are helpful for identifying and fixing those gaps.
As it happens, we have an issue report for this here: https://gitlab.kitware.com/paraview/paraview/-/issues/19636. It will be addressed like any other bug in ParaView. For more info about that process, please see How are features and bug fixes incorporated into ParaView?
Hey @cory.quammen
I always assumed Python tracing required some kind of code-specific-code, to account for the gaps. Nice to see that verified.
I can’t think of them off the top of my head, but there’s at least a few missing captures my users have come across. I should report them as they come up (how else will they get fixed, of course!), but now if I were to come up with a list do you guys prefer I make individual bug reports for each one?
Yes, please. That increases the dopamine hits available from closing issues 
If you do post bugs of missing trace functionaltiy, you may want to reference them from this discourse post. Cory and I will both see them. And thanks for reporting!
@wascott @cory.quammen
I encountered this problem when using SPHVolumeInterpolator. Volume Refinement cannot be traced. Firstly, I would like this to be addressed. Secondly, I need to somehow extract this part, so are there any alternatives that I can implement right now whilst waiting for the bug to be addressed?
I wish to change refinement mode to use cell-size, and change cell size.