created variable section cake collumn

[Pese83]

Good morning.

I would need help in creating a pie column.
I have to draw a column with a 90° twist, and so far everything is simple.
the problem arises from the fact that the column section must shrink up to half height, to return to the starting section at the top (but rotated by 90°).
Also this would not be a problem, I did doing it by performing a sweep with twist and scale factor. Then
copying and overturning the solid obtained and overlapping them, I get the pie column with reduced central section.
In this way, however, the narrowing of the column has a straight pattern while I need it to be curved.
we say that observing the column frontally must have the form of two opposite brackets ----->)(.
I hope I've explained clearly. . .
thank you to those who want to give me some tips!

 

[GP.]

Maybe a piece of dwg, or a sketch on cheese paper.. . .

 

[Pese83]

this is the column with constant section, I need it to tighten to half height and return to the normal section on top.

 

[Cristallo]

The only way that comes to mind is by means of a loft of sections. more sections are more accurate is the result.
In fact, in the "scale" sweep option there is a sub option "expression", but I do not find explanations about its operation.

 

[Joblayer]

the system you used I think is right, maybe you didn't give a proper scale factor to me in principle works.

 

[Pese83]

good idea the loft of sections, but I can't imagine how to get the correct sections "stratum per layer".

 

[Pese83]

the system you used I think is right, maybe you didn't give a proper scale factor to me in principle works.

in that way I managed it too, and it is also simple, but so doing the profile of the column follows a straight line tilted up to half height, then it changes angle and continues always straight, to me it would need to be curved, so " )( " and not " v "
(I hope my hieroglyphs serve to make the concept... ) a

 

[GP.]

[Cristallo's method]- copy a profile in half height and one in top
- the half-scale one of the desired factor and rotate it by 45 degrees
- creates two splines that serve as guides
- loft with "guide" option

 

[Cristallo]

How to say...
when you have a ciulo that reads your problem:

 

[Pese83]

As always you have the solution under your nose, but until someone shows you.. .
and I who was going to get me to think about who knows what unknown command! !
Thank you so much!!

 

[GP.]

...ciulo. ..

Eh... 'on the vorta...