Mesh Generation scripts for Unity Engine.

MeshGeneration.cs

using System;
using UnityEngine;

namespace Game
{
    [RequireComponent(typeof(MeshFilter))]
    [RequireComponent(typeof(MeshRenderer))]
    public class MeshGeneration : MonoBehaviour
    {
        [SerializeField]
        protected MeshFilter meshFilter;
        [SerializeField]
        protected MeshRenderer meshRenderer;

        // Vertex position relative to mesh filter position.
        public Vector3[] vertices;
        // It's array index of vertices, need to be mod by 3. every 3 points should be order by clockwise.
        public int[] triangles;

        private Mesh mesh;

        protected virtual void Awake()
        {
            mesh = new Mesh();
            meshFilter.mesh = mesh;
        }

        protected virtual void Start()
        {
            GenerateMesh();
        }

        public void GenerateMesh()
        {
            mesh.Clear();
            mesh.vertices = vertices;
            mesh.triangles = triangles;
            // I Don't know why this isn't working. Unity still calculate in wrong 
            mesh.RecalculateNormals();
        }

#if UNITY_EDITOR
        protected virtual void OnDrawGizmosSelected()
        {
            for (int i = 0; i < vertices.Length; ++i)
            {
                Gizmos.DrawWireSphere(transform.TransformPoint(vertices[i]), 0.01f);
                UnityEditor.Handles.Label(transform.TransformPoint(vertices[i]), $"{i}:{vertices[i]}", UnityEditor.EditorStyles.miniBoldLabel);
            }
            if (triangles.Length % 3 == 0)
            {
                for (int i = 0; i < triangles.Length && i % 3 == 0; i = i + 3)
                {
                    int i1 = i;
                    int i2 = i + 1;
                    int i3 = i + 2;
                    Gizmos.DrawLine(transform.TransformPoint(vertices[triangles[i1]]), transform.TransformPoint(vertices[triangles[i2]]));
                    Gizmos.DrawLine(transform.TransformPoint(vertices[triangles[i2]]), transform.TransformPoint(vertices[triangles[i3]]));
                    Gizmos.DrawLine(transform.TransformPoint(vertices[triangles[i3]]), transform.TransformPoint(vertices[triangles[i1]]));
                }
            }
        }
        protected virtual void OnValidate()
        {
            if (UnityEditor.EditorApplication.isPlaying)
            {
                try
                {
                    if (mesh != null)
                        GenerateMesh();
                }
                catch (Exception e)
                {
                    Debug.LogException(e);
                }
            }
        }

        protected virtual void Reset()
        {
            meshFilter ??= GetComponent<MeshFilter>();
            meshRenderer ??= GetComponent<MeshRenderer>();
        }
#endif
    }
}