Mesh.uv

Description

The base texture coordinates of the mesh.

#pragma strict
function Start() {
	var mesh: Mesh = GetComponent.<MeshFilter>().mesh;
	var vertices: Vector3[] = mesh.vertices;
	var uvs: Vector2[] = new Vector2[vertices.Length];
	for (var i: int = 0; i < uvs.Length; i++) {
		uvs[i] = new Vector2(vertices[i].x, vertices[i].z);
	}
	mesh.uv = uvs;
}

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    void Start() {
        Mesh mesh = GetComponent<MeshFilter>().mesh;
        Vector3[] vertices = mesh.vertices;
        Vector2[] uvs = new Vector2[vertices.Length];
        
        for (int i=0; i < uvs.Length; i++) {
            uvs[i] = new Vector2(vertices[i].x, vertices[i].z);
        }
        mesh.uv = uvs;
    }
}

Note: Texture coordinates have to be modified or created externally from the mesh. In the script example above the uvs is created as a new array. Then the texture coordinates are assigned to that array. Once these are assigned the array is assigned to the Mesh.