flatten Terrrain under object

This is just a very quick and not optimized script to give you an idea. Place terrain at coordinates 0,0,0; place a FPS Controller on it, attach script to FPS Controller and walk a while. Then press H. Of course, you have to put some more logic to create roads on this way but this is an example how you can manipulate terrains data.

Flatter.cs:

 using UnityEngine;
 using System.Collections;
 
 public class Flatter : MonoBehaviour {
     
     TerrainData terrData;
         
     float[,] heightmapData; // prepare a matrix with terrain points
     float ratio; // ratio between player position and terrain points
     
     // Use this for initialization
     void Start () {
         
         terrData = Terrain.activeTerrain.terrainData;
         int terrRes = terrData.heightmapResolution;
         Vector3 terrSize = terrData.size;
         
         heightmapData = terrData.GetHeights(0, 0, terrRes, terrRes); // heights we will change during of walking
         
         ratio = terrSize.x / terrRes;
         
         Debug.Log ("heightmapData="+heightmapData +" terrRes="+terrRes+" terrSize="+terrSize + " ratio="+ratio);
     }
     
     // Update is called once per frame
     void Update () {
 
         int terrainPointX = Mathf.CeilToInt(transform.position.x / ratio);
         int terrainPointZ = Mathf.CeilToInt(transform.position.z / ratio);
         
         Debug.Log (" terrainPointX="+terrainPointX+" x terrainPointZ="+terrainPointZ +": set height to 0.0");
         
         heightmapData[terrainPointZ,terrainPointX ] = 0.0f; // move terrain point to 0 (example)
 
     }
             
     
     void OnGUI() {
         if (Input.GetKey(KeyCode.H)){
             Debug.Log("Saving");
 
             terrData.SetHeights(0, 0, heightmapData); // save terrain heights back
         }
     }
 }

Thanks. That's just what I needed. I guess that if I kind of throw a grid over ever the entire scene and ray cast vertical collisions, that then I should be able to adjust the entire terrain by that.

Could somebody please make this comment? Thanks ;)