Help with Lisp Drawing Vertical Profile of polyline

Hi, Help needed...

I am very new to writing lisp and i am trying to write a lisp that draws a vertical profile of a horizontal alignment. And have construction lines going vertical at each horizontal bend.

I can get the x y z values of the alignment in list form but i dont know how to then take that information and draw the vertical profile and input construction lines at the horizontal bends.

I have attached a screen print of what im after.

Many thanks

Welcome to CADTutor!

I always find it curious when we get questions about how to achieve Land Desktop, or Civil 3D functionality using vanilla AutoCAD.

In any event, to help answer your complex question, you'll wan to start by looking into the vlax-Curve* and Polar functions to calculate the locations about the horizontal alignment, and the points based on the alignment locations. Making this more complex (to be done well); you'll need a way interact with this data beyond closing, and re-opening the drawing... You need to look into Dictionaries and/or XRecords as a means of storing the data within the Object.

HTH