overlapping 2 volumes in a render window


I have 199 CT slices of the liver (volume 1) from which I have segmented the liver vessels (volume 2: 199 slices containing only the vessels in binary images). Now I want to overlap these 2 volumes: I want to see the liver and my segmented vessels both (highlighting vessels in red, I think a simple look up table will work), but how can I actually perform the overlapping?

Are there any examples / classes I could use?

Thanks in advance for any help!

I would just add the two volumes to the same renderer, if you are using python you can have a look here.

Thanks @marcomusy, it worked! If everyone else need it, I also found out about vtkMultiVolume (that I cant use because I have an old version of VTK :frowning: )