why blue polygon is discarded in fig 3 of main paper?

[sungmin9939]

Thanks for the great work!

I am just wondering why the discarded polygon is not the orange one but the blue one.

In my understanding, non-watertight mesh in fig 3 is modeling a sphere with a hole shaped like a ghost, so i think orange ones should be discarded to extract desired shape.

please let me know where i am getting wrong in my understanding