Procedural Terrain?

This 3 tutorials cover all procedural terrain generation aspects in Unity:

http://kostiantyn-dvornik.blogspot.com/2013/01/unity-4-cool-sweet-terrain-tutorial.html

http://kostiantyn-dvornik.blogspot.com/2013/11/awesome-unity-texturing-terrain-tutorial.html

http://kostiantyn-dvornik.blogspot.com/2014/02/huge-amazing-unity-terrain-tutorial.html

Additional split terrain script:

http://kostiantyn-dvornik.blogspot.com/2013/12/unity-split-terrain-script.html

Automatic grass placement: https://doctrina-kharkov.blogspot.com/2019/08/unity-automatic-grass-terrain.html

Yes, and this has been done with Unity. Let me try to find the link. There was a video and everything. It was done really nicely.

A quick google search yielded it. And it is indeed called procedurally generated terrain. Head to page 2 and its at the bottom.

Here is another procedural generator.

Kind of late, but if you have terrain toolkit I've made a script to generate random textures/heightmaps using terraintoolkit:

 using UnityEngine;
 using System.Collections;
 
 public class PerlinTerrain : MonoBehaviour {
 
     //Toolkit instance.
     [SerializeField]TerrainToolkit kit;
     //Array of textures.
     [SerializeField]Texture2D sandTexture;
     [SerializeField]Texture2D grassTexture;
     [SerializeField]Texture2D rockTexture;
     [SerializeField]Texture2D cliffTexture;
 
     void Start() {
         //Check if we have the kit assigned;.
         if (kit == null) {
             //If there is not an instance assigned or on gameObject, return.
             if (!GetComponent<TerrainToolkit>())
             {
                 return;
             }
             //Else assign kit to gameObject's toolkit.
             else
             {
                 kit = GetComponent<TerrainToolkit>();
             }
         }
         //Generate the terrain.
         Generate();
     }
 
     void OnGUI(){
         if (GUILayout.Button ("Generate")) {
             Generate();        
         }
     }
 
     public void Generate() {
         //Generate the perlin terrain.
         kit.PerlinGenerator((int)Random.Range(3,6),Random.Range(0.4f,0.9f),Random.Range(2,6), 1f);
         //Gives it a less smooth feel.
         kit.PerlinGenerator(4,4,4, 0.1f);
         //Creates arrays for stops.
         float[] slopeStops = new float[2];
         float[] heightStops = new float[4];
         Texture2D[] terrainTextures = new Texture2D[4];
         //Assigns values to the arrays.
         slopeStops[0] = 30f; slopeStops[1] = 70f;
         heightStops[0] = Random.Range(0.05f, 0.18f);
         heightStops[1] = Random.Range(0.19f, 0.49f);
         heightStops[2] = Random.Range(0.5f, 0.69f);
         heightStops[3] = Random.Range(0.7f, 0.89f);
         terrainTextures[0] = cliffTexture;
         terrainTextures[1] = sandTexture;
         terrainTextures[2] = grassTexture;
         terrainTextures[3] = rockTexture;
         //Paints the textures.
         kit.TextureTerrain(slopeStops, heightStops, terrainTextures);
     }
 
     public void Generate(bool doublePerlin) {
         //Generate the perlin terrain.
         kit.PerlinGenerator((int)Random.Range(3,6),Random.Range(0.4f,0.9f),Random.Range(2,6), 1f);
         //Gives it a less smooth feel.
         if(!doublePerlin){
             kit.PerlinGenerator(4,4,4, 0.1f);
         }
         //Creates arrays for stops.
         float[] slopeStops = new float[2];
         float[] heightStops = new float[4];
         Texture2D[] terrainTextures = new Texture2D[4];
         //Assigns values to the arrays.
         slopeStops[0] = 30f; slopeStops[1] = 70f;
         heightStops[0] = Random.Range(0.05f, 0.18f);
         heightStops[1] = Random.Range(0.19f, 0.49f);
         heightStops[2] = Random.Range(0.5f, 0.69f);
         heightStops[3] = Random.Range(0.7f, 0.89f);
         terrainTextures[0] = cliffTexture;
         terrainTextures[1] = sandTexture;
         terrainTextures[2] = grassTexture;
         terrainTextures[3] = rockTexture;
         //Paints the textures.
         kit.TextureTerrain(slopeStops, heightStops, terrainTextures);
     }
     
 }