Spherical coordinates and filters


I am trying to extract a spherical surface from a dataset using paraview 5.8.1 spherical filters. I’m running into a problem that my spherical filter center at (0,0,0) doesn’t extend to the right radius. If I set radius to 1 it does not intersect the point at (1,0,0) but instead intersects at some point below.

I can duplicate this problem using spherical sources where I create one source centered at (0,0,0) with a radius of 1 and another at (1,0,0) with a small radius. The larger one does not intersect the center of the smaller one.

I am confused exactly what is going on and what I can do to get the correct center/radius for my fitler.


I found the issue but I’m not sure how to fix it or why this is the case. I looked into the information section for the sphere with radius 1 centered at (0,0,0) and the bounds are:

X Range: -0.97491 to 0.974928 (delta: 1.94984)
Y Range: -0.97491 to 0.974928 (delta: 1.94984)
Z Range: -1 to 1 (delta: 2)

So for some reason the sphere source isn’t producing a true sphere. Maybe I need to increase the resolution of it somehow? Changing the theta resolution parameter does not fix the issue.

Found the solution. I have to increase the Phi resolution. Hopefully this can help someone else who is new.