Volume is not calculated properly for adaptive family

[milo1986]

Hello everyone,

I have created an adaptive family where I modeled conductor/rope with two placement points (start/end) and two inner points to shape it which are parametrized and used in a project.

In the project (schedules) I calculate a length of conductor using "Volume" and "cross-section" values.

Problem is that volume is not calculated properly when I bent the conductor.

However when I use instead of inner "Reference points" a "Shape Handle Points" volume and lenght are properly calculated in the project. 

Attached you can find the family file.

I would really appreciate if someone could help me what I am missing or doing wrong.

Thank you.

UPDATE 2023-08-24: for better explanation I am sending a picture and project with two conductors (one with parametrized reference points and one with shape handle points) and schedule with LENGTH calculation.

Now I can see that once the conductors are straight length is calculated correctly but when I move reference/shape handle points volume/length are not correct.

Why that behavior?

Thank you for help.