AutoCAD vs Rhino 3D - A very simple comparison
I still use AutoCAD, especially for annotating. I used to use it for 3D. I finally tried a few other programs. Rhino 3D was by far the best (for what I do). For those wondering if it's worth learning, here's a simple comparison. The AutoCAD modelling is sped up; about 3x on average. Rhino modelling is only sped up 2x. If you work it out you'll probably find that Rhino is about 4x faster for this task.
There's 'craftier' ways of doing this in either program. And I'm sure a few "one step" methods. I often find that the "one step" methods fail in more situations than more manual ones.
The AutoCAD process:
With the linework already existing, I trace the linework with "3DPOLY".
Next I close the 3Dpolyline I just created. They are sometimes closed but not usually.
Then I either use PLANESURF or CONVTOSURF (found the later easer) to create a surface from the 3D poly.
I then used "SCULPT" to convert the surfaces into a solid (they have to be touching or this won't work).
And Rhino 3D:
Simply use "SrfPt" to create the faces. Then use "Join". You end up with a solid unless there's a gap somewhere. Should there be a gap it's much easier to solve than with ACAD.
I should note that there are endless ways to do this in Rhino. This is just one way using commands I'm familiar with.