Mesh.bounds

Description

The bounding volume of the Mesh.

This is the axis-aligned bounding box of the mesh in its own space, so the bounds don't change if you change the Transform position, rotation or scale. The Renderer.bounds property is similar but returns the bounds in world space.

Additional resources: Bounds class, Renderer.bounds

// Generates planar UV coordinates independent of mesh size
// by scaling vertices by the bounding box size

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];
        Bounds bounds = mesh.bounds;
        int i = 0;
        while (i < uvs.Length)
        {
            uvs[i] = new Vector2(vertices[i].x / bounds.size.x, vertices[i].z / bounds.size.x);
            i++;
        }
        mesh.uv = uvs;
    }
}