I have a lots of lines or complex chain (non-straight and non-flat)
Is there any way to calculate the total length of all the lines combined? in either Open Building or Open Building Generative Component
(Other than the manual add one by one method)
Are these lines or complex chains connected with each other? If yes then you can use the technique Curve.CompositeCurve & then from there get the length of the composite curve.
From my initial testing, I have found if I consume these elements in Polyline node ByRange then we get the total length.
Here's another way