文章目录

1.概述

本片转自如下

2.代码

using System.Collections;using System.Collections.Generic;using UnityEngine;public class CreateIcosahedron : MonoBehaviour{public float size = 1;private Vector3[] vertices;private Vector2[] uvs;private Vector3[] normals;private Vector4[] tangents;private int[] triangles;private Mesh CreateRegular(){Mesh mesh = new Mesh();// 先按12个顶点开辟顶点数组vertices = new Vector3[12];// 正二十面体顶点公式（度娘可查）float m = Mathf.Sqrt(50 - 10 * Mathf.Sqrt(5)) / 10 * size;float n = Mathf.Sqrt(50 + 10 * Mathf.Sqrt(5)) / 10 * size;// 按公式顺序对顶点坐标赋值vertices[0] = new Vector3(m, 0, n);vertices[1] = new Vector3(m, 0, -n);vertices[2] = new Vector3(-m, 0, n);vertices[3] = new Vector3(-m, 0, -n);vertices[4] = new Vector3(0, n, m);vertices[5] = new Vector3(0, -n, m);vertices[6] = new Vector3(0, n, -m);vertices[7] = new Vector3(0, -n, -m);vertices[8] = new Vector3(n, m, 0);vertices[9] = new Vector3(-n, m, 0);vertices[10] = new Vector3(n, -m, 0);vertices[11] = new Vector3(-n, -m, 0);// 正二十面体三角形的点序列triangles = new int[] {6,4,8, 9,4,6, 6,3,9, 6,1,3, 6,8,1,8,10,1, 8,0,10, 8,4,0, 4,2,0, 4,9,2,9,11,2, 9,3,11, 3,1,7, 1,10,7, 10,0,5,0,2,5, 2,11,5, 3,7,11, 5,11,7, 10,5,7};// 根据面的顺序，重新创建新的顶点数组，用于计算顶点法线Vector3[] newVs = new Vector3[triangles.Length];for (int i = 0; i < newVs.Length; i++){Debug.Log(vertices[triangles[i]]);newVs[i] = vertices[triangles[i]];}vertices = newVs;uvs = new Vector2[vertices.Length];normals = new Vector3[vertices.Length];tangents = new Vector4[vertices.Length];// 根据新的点，设置三角面的顶点ID并计算点法线for (int i = 0; i < triangles.Length - 2; i += 3){Vector3 normal = Vector3.Cross(vertices[i + 1] - vertices[i], vertices[i + 2] - vertices[i]); // 计算点的法线for (int j = 0; j < 3; j++){triangles[i + j] = i + j; // 重新设置面的顶点IDnormals[i + j] = normal; // 点的法线赋值}}// 设置每个点的切线和UVfor (int i = 0; i < vertices.Length; i++){tangents[i] = new Vector4(-1, 0, 0, -1); // 切线uvs[i] = new Vector2(vertices[i].x, vertices[i].y);// UV坐标}mesh.vertices = vertices;mesh.triangles = triangles;mesh.normals = normals;mesh.tangents = tangents;mesh.uv = uvs;return mesh;}private void Start(){MeshFilter mf = GetComponent<MeshFilter>();mf.mesh = CreateRegular();}private void OnValidate(){MeshFilter mf = GetComponent<MeshFilter>();mf.mesh = CreateRegular();}}