When enabling "Mask input points" python crashes/segfaults because it tries to allocate 9223372036854775805 elements of 4 bytes (thats 3,7e19 bytes!).
Error message is:
ERROR: In /tmp/-ShMM/VTK5.10.1/Common/vtkDataArrayTemplate.txx, line 144 vtkFloatArray (0x7ff37757da60): Unable to allocate 9223372036854775805 elements of size 4 bytes.
Seems this is because "Max number of points" is set to 9223372036854775805 by default, and I'ts not possible to change from the mayavi pipeline window (greyed out). Yey!
Anyhow, to fix this, set "Max number of points" before turning masking on. Do it this way:
# Plot fig = figure(1, size=(400, 400), bgcolor=(1, 1, 1), fgcolor=(0, 0, 0)) # figure with white background quiver3d(x,y,z,bx,by,bz) # prevent segfautl (malloc too large) on osx vectors = fig.children.children.children vectors.glyph.mask_points.maximum_number_of_points = 1000 # "Manually" set Maximum number of points vectors.glyph.mask_input_points = True # turn masking on