Dear Jan,
thank you for your feedback.
Unfortunately Offseting 3D curves its not trivial even for 3D polyline, when 3D polyline segments are not in the same plane.
For offseting 3Dcurves/lines/polylines which segments are in same plane, I recommend to use fnc. Parallele zu Element which handles nicely these cases.
When your 3D polyline has segments with different orientation (Z direction segments, sloped,...) this is far more complicated.
Those additional offseted segments created by fnc. Paralleler Linienzug 3D however looks strange but there is a reason for those: When neighboring segments of the Polyline has different orientation together with the definition of the orientation of the offseted segments (taken from the active viewport, e.g. Floor plan) they need to stay parallel to the definition plane, but this causes that these offseted lines has no intersection (skew lines)! see picture, therefore there is a additional segment on the offseted line to connect them.
So without changing the orientation of the offseted segments (not following anymore defined offset plane) there is no way to get result you expects.
Therefore either you may use workaround you mentioned in your comment, or create Individual offseted segments with fnc. Parallele zu Element and then solve manually the connections by extending or shortening the offseted lines to their intersection. However vertical inclined segments needs to be offseted as last because their position needs to be adjusted by considering previous and next segment (offset -> move).
To automate this process to get desired result from my point of view it will require to adjust the specific connections when position of offseted curves/lines are calculated by not yet created = user inputs, additional options needed.
To understand and propose proper solution I would like to ask you to provide more detail requirements + data. (What is the reason, what needs to be modelled, why, and expected results,... )
Thank you
Best regards
Martin Mikus
Product Manager Allplan Architecture
S pozdravom | Best regards | Mit freundlichen Grüßen
Martin Mikus
Product Manager Allplan Architecture