http://littlewing.hatenablog.com/entry/2017/04/28/164655

OpMeshGenerator.cs

using UnityEngine;
using System.Collections;
#if UNITY_EDITOR
using UnityEditor;
#endif

public class OpMeshGenerator : MonoBehaviour
{

    public int divisionX = 200;
    public int divisionY = 200;
    public float sizeX = 5f;
    public float sizeY = 5f;
    public float opCupCoef = 9.6f;
    public string saveAsAnAssetInPath = "Assets/OpMesh.asset";
    Mesh mesh;
    
    Vector3 Op(float x, float y)
    {
        float z = (
            opCupCoef * Mathf.Exp(
                -(
                    Mathf.Pow(2f / 3f * Mathf.Abs(x) - 1f, 2f)
                    + Mathf.Pow(2f / 3f * y, 2f)
                )
                - 1f / 3f * Mathf.Pow(2f / 3f * y + .5f, 3f)
            )
            + 2f / 3f * Mathf.Exp(
                -Mathf.Pow(2.818f, 11f) * Mathf.Pow(
                    Mathf.Pow(Mathf.Abs(2f / 3f * x) - 1f, 2f)
                    + Mathf.Pow(2f / 3f * y, 2f)
                , 2f)
            )
            - Mathf.Pow(2f / 3f * x, 4f)
        ) / 8f;
        return new Vector3(x, y, -z);
    }

    Mesh CreateMesh()
    {
        int countX = divisionX + 1;
        int countY = divisionY + 1;
        var vertices = new Vector3[countX * countY];
        var uv = new Vector2[countX * countY];
        int k = 0;
        for (int i = 0; i <= divisionY; i++)
        {
            for (int j = 0; j <= divisionX; j++)
            {
                float u = (float)j / divisionX;
                float v = (float)i / divisionY;
                float x = (u - .5f) * sizeX;
                float y = (v - .5f) * sizeY;
                vertices[k] = Op(x, y);
                uv[k++].Set(u, v);
            }
        }

        var triangles = new int[6 * divisionX * divisionY];
        int l = 0, kTL = 0, kTR = 1, kBL = countX, kBR = countX + 1;
        for (int i = 0; i < divisionY; i++)
        {
            for (int j = 0; j < divisionX; j++)
            {
                triangles[l++] = kTL;
                triangles[l++] = kBL++;
                triangles[l++] = kBR;
                triangles[l++] = kTR++;
                triangles[l++] = kTL++;
                triangles[l++] = kBR++;
            }
            kTL++; kTR++; kBL++; kBR++;
        }

        if(mesh != null)
            mesh.Clear();
        mesh.name = "OpMesh";
        mesh.vertices = vertices;
        mesh.uv = uv;
        mesh.triangles = triangles;

        return mesh;
    }

    void Start()
    {
        mesh = new Mesh();
        mesh = CreateMesh();
        /*
         //起動時にMeshをAssetに保存する
        if (saveAsAnAssetInPath != "")
        {
            AssetDatabase.CreateAsset(mesh, saveAsAnAssetInPath);
            AssetDatabase.SaveAssets();
        }
        */
        // ここから削除可 ↓↓↓↓↓
        var filter = GetComponent<MeshFilter>();
        if (filter == null) filter = gameObject.AddComponent<MeshFilter>();
        filter.sharedMesh = mesh;

        var renderer = GetComponent<MeshRenderer>();
        if (renderer == null)
        {
            renderer = gameObject.AddComponent<MeshRenderer>();
        }
        if (renderer.material == null)
        {
            renderer.material = Resources.Load("Default-Material", typeof(Material)) as Material;
        }
        CreateLight("Key Light", 60f, 100f, 1f, 1f, 1f);
        CreateLight("Fill Light", 30f, -100f, 1f, .8f, .6f);
        // ここまで削除可 ↑↑↑↑↑
        
    }
    private void Update()
    {
        mesh = CreateMesh();
    }

    // ここから削除可 ↓↓↓↓↓
    void CreateLight(string name, float rx, float ry, float r, float g, float b)
    {
        var obj = new GameObject();
        obj.name = name;
        var light = obj.AddComponent<Light>();
        var euler = new Vector3(rx, ry, 0f);
        var pos = transform.position + Op(0f, 0f);
        light.type = LightType.Directional;
        light.transform.localRotation = Quaternion.Euler(euler);
        light.transform.position = pos + Quaternion.Euler(-euler) * Vector3.forward * 10f;
        light.color = new Color(r, g, b);
        light.intensity = 1f;
        light.bounceIntensity = 0f;
        light.shadows = LightShadows.Soft;
    }
    // ここまで削除可 ↑↑↑↑↑

}