I have a
polyline, and i want to add
point (vertex) on a specific distance, like two meters for example.
How can i do that?
You should use the IPolyCurve:SplitAtDistance Method. This
Adds a new vertex point to the curve at a specified distance from the From point of the curve. For a split to happen, the split distance must be between the From and To points of the polycurve.
Just remember to set the CreatePart to false. This way the polyline will not be split, but just a new vertex added.