[vtkusers] opacity: problem with overlapping actors

[Rex.Schilasky at contiteves.com]

Hi,

    in my application I have multiple actors
    in one renderwindow (it's normal I think :-) ).
    Some of the actors are overlapping (in my
    case for example a plane under a sphere). If
    I set the opacity of this overlapping actors
    on the same value less than 1.0 (for example
    0.8) then the front actor becomes nearly
    transparent. If I then reduce the opacity
    of the background actor, the front actor
    is getting more opaque. What happens here ?

    Thanx for any suggestions

    ReX