The "Unity3D Polyline Editor" is a unity editor that is used to create a polyline/path that can be used in any 2D project.

Download the unity package from unity Asset Store

• Add the Polyline script to any game object, the polyline will initialized by two points ([-3,0,0] and [3,0,0]).
• Begin dragging your nodes in the scene view to the desired position (you may need to switch to the 2D tool instead of the default move tool to be able to drag the nodes).
• To add a new node press and hold on Shift key then move the mouse to desired location, the editor will show you the two nodes that your new node will inserted between them, click the mouse left button to add the node.
• To delete node press and hold the Ctrl key and move the mouse to the node that you want to delete, then click the left mouse button.
• Getting the edit nodes by code is very easy, you need to get the Polyline component of the object and it contains a public List<Vector3> called Node that contains your nodes (check the Example1_Path).

Example1_Path This is a very basic example of Polyline usage in which the Polyline editor used to create a path, and the Cube Object follow this path. The code behind the path follow is written in the PathMovement script, this script has a reference to a Polyline script called path and we set it in the inspector. In Updatefunction the PathMovement script check the next target point form the path and alter the cube velocity, then move it with this velocity.

Example2_Simple2DTerrainEditor This is more complex example in which the Polyline editor customized and the code changed. You will find a new version of PolylineEditor script called Simple2DTerrainEditor and a different version of Polyline script called Simple2DTerrain. All the changes are in Simple2DTerrainEditor in which the there is a Function called UpdateTerrain this function called whenever the polyline/terrain vertices changed (that happened when any node moved, added or deleted). The UpdateTerrain function will use a Traingulator to calculate the new mesh triangles and update the Mesh of the MeshFilter component assigned to the Terrain.