draw outline for some connected lines

Question

I have some lines that are connected at various points. I want to draw the outline of these lines and I also want to deal with the extra lines at the connection points.

I have seen two similar questions in this website: Here and here

I have handled the normal cases by offsetting the Centerlines and then changing the start and end points of the lines.

but I haven't been able to deal with special cases when the points are near each other.

Unfortunately, my reputation is low I couldn't post images to explain this better.

I'm coding in Visual Basic .net and I'm writing for Autocad, but any advice will be very useful to me.

Answer 1

most problem cases are solved by translation vectors intersection check

• black is the original line/curve whatever ...
• gray is translation vector (normal to black and size = outline distance)
• blue is outline

if the translation vectors not intersect then it is most likely all OK but if they do then just do something like this:

1. cut off these points from outline

2. or create some singular point from these intersections

   it is more tricky but can avoid some problem cases from bullet #1

Also sometimes help if there is bigger density of control points

Hope it helps a little...