Different color for different field lines

Hello, I have a netcdf file which contain Bz component of magnetic field image and a data array with voxels containing Bx,By and Bz component. I want to color the open and closed field lines differently. How could I do that?

here is the pfe.nc file :

Hmm. If my understanding is correct, I don’t believe this is possible because the Flow renderer has no notion of an open or closed streamline. If you like, you could submit a feature request, however I think it would be fairly tricky to implement since the odds of a streamline’s start and end points being the same are extremely low.

Sorry I can’t be more helpful. If you do find an alternative solution, I’d be curious to know what that is.

Hi, I used python to differentiate closed (starting and emitting surfaces are same) and open field lines after collecting field lines drown using vapor. I am new to vapor and struggling to use python script as well. I need to access z coordinate variable. I am able to access only x coordinate only after writing x = x*Bx/Bx otherwise getting error as the screenshots I am posting.
Following paper used vapor to do that (figure 12.a2) so something definitely can be done. I wrote that netcdf file so I am not sure if there is any problem in the file.


I just wanted to let you know I haven’t forgotten about this. I need to carve out some time next week to take a closer look at your use case. Stay tuned.

Hi, I resolved that. Using 2 different seeds (one for open and one for closed) for different renderers and using different colors would work. Thanks btw for kind consideration.

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Interesting. Were you only able to do this by knowing which seeds were open and closed by trial and error? I can’t think of another way to do this aside from guessing and checking.

I extracted all the flowlines and then based on some criteria like length , monotonicity and height-truncation etcetera in python, I sorted out open and closed field lines’ seeds and then used those seeds to plot.

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