Need help with seamless modelling

Hello guys so I am trying to model some structure that look like these zaha haddid but I cannot findout how to do this using only the rhino tools.

Maybe I could do this by using Tsplines plugin but I cannot afford it at the moment, so I need it to be able to do this in Rhino.

Someone can help me?

i think you can trial tsplines free for 30 days free. check it out

I suspect that the problem is: you believe it’s seamless.

The first picture is not all that clear, but perhaps trying thinking about it split separating the outside to inside, as if you made two mess-hall lunch trays, cut the bottoms out, and welded (create solid) them together, and filleted the edges.

The second pic is probably harder to do, but it appears that it can be done with mitred sweeps, made from cross sections. If you can’t think of it being chopped it on the straightaways–attack it on the intersections, or vice-versa.

[As an armchair engineer, I should think that the second building would be hard to make because so much of the roof is cantilevered, unless it’s pulled from the top.]