Hi iolofato, well for the surface shaping to be correct you can do that by creating a vertical line for your sweep profile:



Run Construct > Sweep, select the one helix curve for the sweep rail path, then set the Twist: Flat option:



So now you'll have the problem with your pattern being distorted. Maybe a good solution would be to make 2 versions, one with your "good for flow but with concave silhouette" and generate solids using Flow on that one, and use those to cut out from this straight sided one.

When you make the objects to use as boolean cutters, make them stick out some distance from the surfaces, don't make the cutting objects have overlapping surface areas with the base object.

Would that combination method be workable? I guess another possibility would be to incorporate a kind of italic text like slanting effect as part of the pattern flow.

- Michael

Hi iolofato, so yes the concave shaping that you're seeing is due to "ruling line twisting" like I was showing above (http://moi3d.com/forum/index.php?webtag=MOI&msg=10257.3)

It's a type of shaping effect you can get on a ruled surface (a surface made up of straight lines connecting between 2 curves) if the ruling lines are not restricted.

If you turn on your surface control points you can see yours is similar:



- MIchael

Thanks a lot to all of you, I'm sure your remarks will be really helpful ;-)

For build a same line distance "Flat" to Flow
you can Array Curve a Point along a curve (here an helix)
and cut the curve at the wished distance...