Terrain: Paint on Terrain between 2 or more Vector3?

Unity Engine
1

hey! I am actually pretty new to Terrain modification so please excuse this question if it might be stupid.

So what i wanna do now is, i have an array of Vector3s. like this:

and now i “simply” wanna paint a line on the terrain from Element 0 to element 1 to element 2 …to 3… and so on.

if you are interested what i need this for. i wanna paint roads on a dynamic generated terrain. which looks like this:

the green line is the A* debug path which goes from village to village. and all i wanna do now is paint it

2

so. i will just answer myself - or better give a status update since its not done yet.
what i got so far is this (or what i found on the interwebs so far…):

using UnityEngine;
using System.Collections;


public class PaintRoad : MonoBehaviour {

    float[,,] element;
    int mapX, mapY;
    TerrainData terrainData;
    Vector3 terrainPosition;
    public Terrain myTerrain;
    float[,,] map;
    private Vector3 lastPos;

    void Awake()
    {
        map = new float[myTerrain.terrainData.alphamapWidth, myTerrain.terrainData.alphamapHeight, myTerrain.terrainData.alphamapLayers];

        element = new float[10, 10, myTerrain.terrainData.alphamapLayers];
        terrainData = myTerrain.terrainData;
        terrainPosition = myTerrain.transform.position;

        lastPos = transform.position;
    }

    void Update()
    {
        UpdateMapOnTheTarget();
    }

    void UpdateMapOnTheTarget()
    {
        //just update if you move
        if(Vector3.Distance(transform.position, lastPos) > 1)
        {
            print("paint");
            //convert world coords to terrain coords
            mapX = (int)(((transform.position.x - terrainPosition.x) / terrainData.size.x) * terrainData.alphamapWidth);
            mapY = (int)(((transform.position.z - terrainPosition.z) / terrainData.size.z) * terrainData.alphamapHeight);

            map[mapY, mapX, 0] = element[0, 0, 0] = 0;
            map[mapY, mapX, 1] = element[0, 0, 1] = 1;

            myTerrain.terrainData.SetAlphamaps(mapX, mapY, element);

            lastPos = transform.position;
        }
    }

}

put this on a cube that is on/over your terrain and move this cube(in play mode).
this will paint something black on the terrain where the cube is.

now i only need to find a way to paint from a list of Vectors?