Unity3D之Mesh（一）绘制三角形

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


//1.当将TestTriangle的代码挂在GameObject上的时候，会自动添加这两个组件。
//2.当要移除MeshRenderer或MeshFilter的时候，编辑器会提示不能移除。//如果要移除，先移除TestTriangle脚本之后，才能移除。
[RequireComponent(typeof(MeshRenderer), typeof(MeshFilter))]

public class TriangleMesh : MonoBehaviour
{
    void Start()
    {
        Mesh mesh = new Mesh();
        MeshFilter meshFilter = new MeshFilter();
        meshFilter = GetComponent<MeshFilter>();

        Vector3[] vertices = new Vector3[4];
        vertices[0] = new Vector3(0, 0, 0);
        vertices[1] = new Vector3(0, 1, 0);
        vertices[2] = new Vector3(1, 1, 0);
        vertices[3] = new Vector3(1, 0, 0);

        int[] triangles = new int[3 * 3];
        triangles[0] = 0;
        triangles[1] = 1;
        triangles[2] = 2;
        triangles[3] = 2;
        triangles[4] = 1;
        triangles[5] = 3;
        triangles[6] = 2;
        triangles[7] = 1;
        triangles[8] = 0;

        mesh.vertices = vertices;
        mesh.triangles = triangles;
        meshFilter.mesh = mesh;
    }   
}

Explanation：

1. RequireComponent这一行，表示我们需要MeshRenderer和MeshFilter这两个组件，当我们将TestTriangle的代码挂在GameObject上的时候，会自动添加这两个组件。而我们要移除MeshRenderer或MeshFilter的时候，编辑器就会提示不能移除。