vtkMarching cube will split the surface when surface close to (0, 0, 0)

[wuzhuobin]

vtkMarchingCube seems to begin from the world coordinate (0, 0, 0). then any label image data which be done marching cube will get splited or messed up by the world coordinate (0, 0, 0).
So to avoid this, try not to label near the coordinate (0, 0, 0) or translate your image.

this happens in the vtkvmtkCurvedMPRImageFilter which set (0, 0, 0) in the middle of its curved image. So if doing marching cube, the surface is split 4 parts

[wuzhuobin]

Set the output image's origin to (0, 0, 0) can be a temporary fixation.