I've set up a curve where at some points 3 or even 4 curves meet at a junction:
When I try to convert this to an actual shape:
I get both:
- really ugly corners,
- 'twisted' tubing: the square tubing before and after a junction do not align nicely.
So, my two (related) questions are:
a) how can I create the intended shape with corners that line up nicely and?
b) how can I how can I control the rotation/orientation of the tubing along the curve?
Are curves maybe the wrong tool for this job?

