[vtkusers] Isosurface opacity problem

[cutelee]

Dears

I visualized isosurface using vtkMarchingContourFilter from
vtkUnstructuredGrid.

When the opacity is 1.0 , created picture looks normal.

But when i adjust opacity to below 1.0, the picture has speckles depends
on the position.

Do you have any solution ?

I'll really appreciate it.

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