Assuming you have selected the existing curves as pairs:
Curve.PointAtParameter with parameters 0 and 1 using correct lacing and list levels to get both the start and end point of each curve.
Flatten the list or otherwise restructure it so the points are sets of four points in a sublist for each pair of lines
Line.ByBestFitThroughPoints node to draw the line you are after.
Before this point you need to group your lines in pairs. The list should look like this:
Right now it looks like this: [crv1,crv2,crv3,crv4,crv5,crv6]
For the point at parameter, use a list of 0 and 1 with lacing set to cross product. This will put the points into one sublist of four points for each pair of curves.
Line.ByBestFitThroughPoints will be straight forward.
I really need to write a script that can create mid line between two lines of AutoCAD link in Revit.
As I can see you have used some custom nodes and packages that I can’t find them. Could you please send this Dynamo script that it’s picture shown here? or any help that I can create this script?
Thanks in advance.