I'm having a hard time: I'm creating a middle line in the center of a road route, to verify the distance traveled by trucks. To do this, I create a 3dpolyline by connecting the edges of the path and then create a 3D POLYLINE by clicking on the midpoint of each polyline to draw a median route. As they are many, it is being a complicated job, since I have to click on the midpoint of each one to generate the 3D line that I need. Is there any lisp that can already do this, remembering that it needs to be 3D?