板を1メッシュで大量に生成するC#スクリプト

GenerateManyPlane.cs

    using System.Collections;
    using System.Collections.Generic;
    using UnityEngine;

    #if UNITY_EDITOR
    using UnityEditor;

    /// <summary>
    /// エディター拡張
    /// </summary>
    [CustomEditor(typeof(GenerateManyPlane))]
    public class GenerateManyPlaneInspector : Editor
    {
        public override void OnInspectorGUI()
        {
            var generateManyPlane = target as GenerateManyPlane;

            // 頂点数表示
            EditorGUILayout.LabelField("VertexCount", generateManyPlane.VertexCount.ToString());

            // メッシュ作成ボタン
            EditorGUI.BeginDisabledGroup(!EditorApplication.isPlaying);
            if (GUILayout.Button("Generate Mesh"))
            {
                generateManyPlane.GenerateMesh();
            }
            EditorGUI.EndDisabledGroup();


            base.OnInspectorGUI();
        }
    }
    #endif

    /// <summary>
    /// 板を1メッシュで大量に生成するC#スクリプト
    /// </summary>
    [RequireComponent(typeof(MeshFilter))]
    [RequireComponent(typeof(MeshRenderer))]
    public class GenerateManyPlane : MonoBehaviour
    {
        [SerializeField] bool generateMeshOnUpdate = false; // 毎フレームメッシュを生成するかどうか
        [SerializeField] int zCount = 16; // z方向のPlaneの個数
        [SerializeField] float zSize = 1f;
        private Mesh mesh;
        public int VertexCount { get { return zCount * 4; } } // 頂点数
        public int TriangleCount { get { return zCount * 6; } } // 頂点インデックス数

        void Start()
        {
            mesh = new Mesh();
            GetComponent<MeshFilter>().mesh = mesh;

            GenerateMesh();
        }

        void Update()
        {
            if (generateMeshOnUpdate)
            {
                GenerateMesh();
            }
        }

        /// <summary>
        /// メッシュ作成
        /// </summary>
        public void GenerateMesh()
        {
            if (zSize < 0f) { zSize = 0f; }
            if (zCount < 1) { zCount = 1; }

            float planeInterval = zSize / zCount;

            // 頂点(vertices)作成・UV作成
            int vi = 0;
            Vector3[] vertices = new Vector3[VertexCount];
            Vector2[] uv = new Vector2[vertices.Length];
            Vector3 vertexOffset = new Vector3();
            for (int zi = 0; zi < zCount; zi++)
            {
                vertexOffset.z = planeInterval * zi;

                // 反時計回りに並べる
                vertices[vi + 0] = new Vector3(+1f, +1f, 0f) + vertexOffset; // 0
                vertices[vi + 1] = new Vector3(+1f, -1f, 0f) + vertexOffset; // 1
                vertices[vi + 2] = new Vector3(-1f, -1f, 0f) + vertexOffset; // 2
                vertices[vi + 3] = new Vector3(-1f, +1f, 0f) + vertexOffset; // 3

                uv[vi + 0] = new Vector2(1f, 1f); // 0
                uv[vi + 1] = new Vector2(1f, 0f); // 1
                uv[vi + 2] = new Vector2(0f, 0f); // 2
                uv[vi + 3] = new Vector2(0f, 1f); // 3

                vi += 4;
            }

            // 頂点インデックス(triangles)作成
            int ti = 0;
            int[] triangles = new int[TriangleCount];
            int triangleOffset = 0;
            for (int zi = 0; zi < zCount; zi++)
            {
                triangles[ti++] = 0 + triangleOffset;
                triangles[ti++] = 1 + triangleOffset;
                triangles[ti++] = 2 + triangleOffset;
                triangles[ti++] = 2 + triangleOffset;
                triangles[ti++] = 3 + triangleOffset;
                triangles[ti++] = 0 + triangleOffset;

                triangleOffset += 4;
            }
            mesh.vertices = vertices;
            mesh.uv = uv;
            mesh.triangles = triangles;
        }
    }

1メッシュで板を大量に生成するC#スクリプトです。