Weird holes for visualization (possible issue with xfm)

[zhuang0409]

As the figure, I got weird 'holes' during visualization.
I used pycortex=1.3. or 1.2.x (the issue is unrelated to the version).

I test the visualization by using all ones data. The 'holes' are still there. (the issue is unrelated to my results).

I guess the issue is due to the misalignment (xfm file). Does anyone know how to fix it? Thanks so much in advance.