BREAK multiple lines at the intersection of another line and find CENTERLINE

[brldar001]

Question 1) I have multiple lines that needed to be broken with out a gap. How to do this?

Need to break all green lines into separate lines at the middle yellow line. I need to extract the bottom half of lines and then the top. How can I do this? BREAK command isn't great. Thanks

Question 2)

How can (using same image as about) find a common line that falls between the top white line and the bottom yellow line to create a middle line or centerline (average) that I can edit. Is it possible? I am trying to make in fill contours and I have offset but then they look too similar to the line I just offset. Is there a command to do such? If I use the CENTERLINE command it breaks up my polyline into small individual segments but I need the whole line. 

[Alfred.NESWADBA]

Hi,

do you have AutoCAD Map 3D or AutoCAD CIvil 3D, then your first question can be answered with command _MAPBREAK (or _MAPTRIM and doing it twice to get the objects on different layers).

For your question 2: there might be some tools out which can do that, I personally think it's not possible as long as you don't specify what you see as "mid between 2 none parallel lines". One sample: what is the mid-line of that:

(and that is just one of hundreds of difficult geometry situations to be defined)

- alfred -