Segment rotation with different angles (look at picture)

segments rotation with different (22.9 KB)


i’ve benn already helped throw with this topic, but it doesn’t work with what i wanna do now.
i change a little bit my inicial definition and that’s why it’s working weird. i need to do what i’m showing in the picture, like i’m making the segments rotate like compressing from the endpoints of the polyline, not just from one endpoint. segments in the down-side are more close angles, segments in upper-side are more open angles.