[vtkusers] why i can't see the 3d model?

[Chenzhuo]

Hi,all users
I have a series of 8 bits BMP images which are full of
every grayscale value which is from 0 to 255.Now I
want to build a 3d model of the areas whose grayscale
value are all 255.But when I use vtkMarchingCubes to
build the model and input the parameter of function
vtkMarchingCubes::SetValue(int i,float value) with
255,I see nothing in the view area.I don't know
why,who can tell me the reason.Thanks a lot!

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