The picture attached does a better job at explaining my problem than I could in writing. I simply need to bridge the gap between the top (separated) and bottom (single) volumes.
The tricky bit is working out how to get from a single cross section to multiple ones. Maybe I’m thinking about this in the wrong way?
Ideally a continuation of the existing surfaces. Similar to the way blend finds as smooth a transition as possible. Basically no hard angles. Is this what you mean?
What did you use to model this? Did you started with curves?
The objects seems to be extremely heavy for the smooth geometry I can see. Is it because there is some kind of surface texture you want to capture?
From what I can understand from the image, it would be better to model four individual objects, without the horizontal gap, and then merge them together with some surface trimming between them.