[vtkusers] transparent part of DataSet according to attribute data

[Michael Hilbinger]

Hello!
I have a vtkDataSet with associated AttributeData. The AttributeData  
represents the distribution of a phase in the geometry. I would like to  
display the geometry with parts transparent according to the value of the  
AttributeData -> obtaining the 3D-distribution of the phase in the  
geometry. I tried to perfom this via a LookupTable and a AlphaValue of 0  
for the appropriate value, but the result is not very convincing. Only the  
dsitribution on the outer surface of the geomtry is mapped/rendered  
correctly and no information about what's happening "inside". I already  
pondered upon a combination with vtkContourFilter, but that failed also.  
Can anybody help?
Best regards
m.