how to merge Polyline

[reithinger]

Hi,

I have an exemple.

I have 2 Polyline the red and the blue.

I want to get the green polyline.

Have you any Idea how can i make this ?

Thanks in advance

Fabrice

[Norman_Yuan · Accepted solution]

Here are 2 approaches:

1. Test 2 polyline's intersection points (you should find 2 intersection points in this case); then use Curve.GetSplitCurves() to split the 2 polylines (i.e. the rectangle polyline would be split into 2 parts, while the pass-through polyline would be split into 3 parts.; then use Entity.JoinEntity() to merge the middle part of the pass-through polyline with either half of the rectangle polyline.

2. if you can obtain a point inside the green area (any point your code can identify that is inside the area; or simply ask user to pick anywhere inside), then call Editor.TraceBoundary(). This would be similar as running "BOUNDARY" command.

[reithinger]

Hi Norman,

when you have a solution to take a point in the green area (without user pick) it were perfekt.

[kerry_w_brown]

@reithinger 

Fabrice,

For interests sake, what criteria determines the correct side to choose ?

Stay well,

[reithinger]

Hi Kerry,

That my problem, i don't know...

The best way is to use the TraceBoundary but you must find the right point to use...

Sorry i can't answer you..

[_gile · Accepted solution]

Hi,

You use or get inspired by the TrySlice method of the Polygon2d class from GeometryExtensions library.

[ActivistInvestor]

The only way you can solve the problem is to know which side of the green Arc you are interested in finding a closed boundary with. You need to supply all of the input order to obtain the result.