Transparency of box
test regular field -> viewer 3D
In test regular field choose 3D, in Display choose box and in Datamap choose a variable for Transparency. Even if Opacity is not equal 1 box is not transparent.
test regular field -> regular to irregular field -> viewer 3D
In test regular field choose 3D. In regular to irregular field in Display choose some transparency. The result is attached in a file. regularToIrregularField