最近发现Mesh很牛的样子，虽然以前也见过人家大牛用这个写过工具，当时没大在意，现在开始接触，觉得挺好玩的，首先先上我画的几个图：

Mesh编程基础

据说还可以画各种形状，原理就是所有图形都是由三角形组成的。

下面我们一一的解释下：

一.画三角形

首先，给组件添加MeshFilter和MeshRenderer两个组件，这两个组件是Mesh必须的，然后我们自己新建一个材质备用，用来给Mesh赋值使用，Mesh画出来图案的材质就是你你新建的材质。

重要的两步：

第一步：指定定点，比如我们画三角形，我们指定三个定点

第二部：指定三角形顺序，注意个triangles的数组的大小必须是3的倍数，然后三角形的点顺序必须是顺时针的，当然你逆时针只能在反面看到。

下面我们看下脚本：




void DrawTriangle()



    {



        gameObject.AddComponent<MeshFilter>();



        gameObject.AddComponent<MeshRenderer>();



        gameObject.GetComponent<MeshRenderer>().material = mat;



 



        Mesh mesh = GetComponent<MeshFilter>().mesh;



        mesh.Clear();



 



        //设置顶点




        mesh.vertices = new Vector3[] { new Vector3(0, 0, 0), new Vector3(0, 1, 0), new Vector3(1, 1, 0) };



        //设置三角形顶点顺序，顺时针设置




        mesh.triangles = new int[] { 0, 1, 2 };



    }

最终图片如图所示：

Mesh编程基础

三角形还是比较简单的，Unity官网API介绍就有这个实例，这里面我们暂时先不考虑UV.

二.画正方形

有了三角形，我们画正方形也会简单很多，我们分析一下正方形是由两个三角形组成的，我们画两个三角形就可以了，在上面的基础上我们再加一个点（1,0）就可以了，

代码如下：




#region 画正方形



    void DrawSquare()




    {



        gameObject.AddComponent<MeshFilter>();



        gameObject.AddComponent<MeshRenderer>();



        gameObject.GetComponent<MeshRenderer>().material = mat;



 



        Mesh mesh = GetComponent<MeshFilter>().mesh;



        mesh.Clear();



 



        mesh.vertices = new Vector3[] { new Vector3(0, 0, 0), new Vector3(0, 1, 0), new Vector3(1, 1, 0), new Vector3(1, 0, 0) };



        mesh.triangles = new int[]



        { 0, 1, 2,



          0, 2, 3




        };



    }



    #endregion

图形如图：

Mesh编程基础

正方形能画，那什么梯形，平行四边形，菱形啥的肯定也不在话下，这里我就不写demo了。

三.画圆

一开始画圆还没啥头绪，后来想想，圆其实也是有很多个三角形组成的，类似这样：

鄙人画画比较丑，将就着看吧，类似这样可以细分成很多个小三角形，然后定点坐标就是各点组成：

Mesh编程基础

顶点的集合有黄色的点组成，除了圆心，其它的点的坐标都是根据角度确定的，这个我们上学时几何学过，我就不细说了。

这样我们的画圆的函数需要参数有：半径，圆心坐标，分割的份数

顶点的代码如下：




//顶点



        Vector3[] vertices = new Vector3[segments + 1];



        vertices[0] = centerCircle;



        float deltaAngle = Mathf.Deg2Rad * 360f / segments;



        float currentAngle = 0;



        for (int i = 1; i < vertices.Length; i++)



        {



            float cosA = Mathf.Cos(currentAngle);



            float sinA = Mathf.Sin(currentAngle);



            vertices[i] = new Vector3(cosA * radius + centerCircle.x, sinA * radius + centerCircle.y, 0);



            currentAngle += deltaAngle;



        }

Deg2Rad相当于2PI

后面就是顶点的顺序了，注意，最后一个三角形的定点涉及到初始的点：

比如我们图中的：

Mesh编程基础

如图中所示，最后一组的时候如果使用遍历，数组会越界，所以我们可以最后三个单独写，也可以采用取模。

这里我们的代码采用单独写的方式，代码如下：




//三角形



        int[] triangles = new int[segments * 3];



        for (int i = 0, j = 1; i < segments * 3 - 3; i += 3, j++)



        {



            triangles[i] = 0;



            triangles[i + 1] = j + 1;



            triangles[i + 2] = j;



        }



        triangles[segments * 3 - 3] = 0;



        triangles[segments * 3 - 2] = 1;



        triangles[segments * 3 - 1] = segments;

这样我们的顶点和三角形都确定了，关于顺时针和逆时针，看你摄像头看的哪一面哈

完整的画圆代码如下：




#region 画圆



    /// <summary>




    /// 画圆




    /// </summary>




    /// <param name="radius">圆的半径</param>




    /// <param name="segments">圆的分割数</param>




    /// <param name="centerCircle">圆心得位置</param>




    void DrawCircle(float radius, int segments, Vector3 centerCircle)




    {



        gameObject.AddComponent<MeshFilter>();



        gameObject.AddComponent<MeshRenderer>();



        gameObject.GetComponent<MeshRenderer>().material = mat;



 



        //顶点




        Vector3[] vertices = new Vector3[segments + 1];



        vertices[0] = centerCircle;



        float deltaAngle = Mathf.Deg2Rad * 360f / segments;



        float currentAngle = 0;



        for (int i = 1; i < vertices.Length; i++)



        {



            float cosA = Mathf.Cos(currentAngle);



            float sinA = Mathf.Sin(currentAngle);



            vertices[i] = new Vector3(cosA * radius + centerCircle.x, sinA * radius + centerCircle.y, 0);



            currentAngle += deltaAngle;



        }



 



        //三角形




        int[] triangles = new int[segments * 3];



        for (int i = 0, j = 1; i < segments * 3 - 3; i += 3, j++)



        {



            triangles[i] = 0;



            triangles[i + 1] = j + 1;



            triangles[i + 2] = j;



        }



        triangles[segments * 3 - 3] = 0;



        triangles[segments * 3 - 2] = 1;



        triangles[segments * 3 - 1] = segments;



 



 



        Mesh mesh = GetComponent<MeshFilter>().mesh;



        mesh.Clear();



 



        mesh.vertices = vertices;



        mesh.triangles = triangles;



    }



    #endregion

当然你还可以做点小变动，画成这样：

Mesh编程基础

上面的毁了，这样的就自然能画出来，自己试下哈。

四.画圆环

既然，上面的圆画出来了，圆环也就在此基础上，只不过有好多小梯形组成，梯形由两个三角形组成。

示意图如下：

当分成很多等份时，就类似圆环了。

同理，我们先列顶点，这一次我们比上面多要一个参数，内圆半径：

顶点代码如下：




//顶点



        Vector3[] vertices = new Vector3[segments * 2];



        float deltaAngle = Mathf.Deg2Rad * 360f / segments;



        float currentAngle = 0;



        for (int i = 0; i < vertices.Length; i += 2)



        {



            float cosA = Mathf.Cos(currentAngle);



            float sinA = Mathf.Sin(currentAngle);



            vertices[i] = new Vector3(cosA * innerRadius + centerCircle.x, sinA * innerRadius + centerCircle.y, 0);



            vertices[i + 1] = new Vector3(cosA * radius + centerCircle.x, sinA * radius + centerCircle.y, 0);



            currentAngle += deltaAngle;



        }

同理，再列出三角形：




//三角形



        int[] triangles = new int[segments * 6];



        for (int i = 0, j = 0; i < segments * 6; i += 6, j += 2)



        {



            triangles[i] = j;



            triangles[i + 1] = (j + 1) % vertices.Length;



            triangles[i + 2] = (j + 3) % vertices.Length;



 



            triangles[i + 3] = j;



            triangles[i + 4] = (j + 3) % vertices.Length;



            triangles[i + 5] = (j + 2) % vertices.Length;



        }

最终结果如图：

完整的代码如下：




#region 画圆环



    /// <summary>




    /// 画圆环




    /// </summary>




    /// <param name="radius">圆半径</param>




    /// <param name="innerRadius">内圆半径</param>




    /// <param name="segments">圆的分个数</param>




    /// <param name="centerCircle">圆心坐标</param>




    void DrawRing(float radius, float innerRadius, int segments, Vector3 centerCircle)




    {



        gameObject.AddComponent<MeshFilter>();



        gameObject.AddComponent<MeshRenderer>();



        gameObject.GetComponent<MeshRenderer>().material = mat;



 



        //顶点




        Vector3[] vertices = new Vector3[segments * 2];



        float deltaAngle = Mathf.Deg2Rad * 360f / segments;



        float currentAngle = 0;



        for (int i = 0; i < vertices.Length; i += 2)



        {



            float cosA = Mathf.Cos(currentAngle);



            float sinA = Mathf.Sin(currentAngle);



            vertices[i] = new Vector3(cosA * innerRadius + centerCircle.x, sinA * innerRadius + centerCircle.y, 0);



            vertices[i + 1] = new Vector3(cosA * radius + centerCircle.x, sinA * radius + centerCircle.y, 0);



            currentAngle += deltaAngle;



        }



 



        //三角形




        int[] triangles = new int[segments * 6];



        for (int i = 0, j = 0; i < segments * 6; i += 6, j += 2)



        {



            triangles[i] = j;



            triangles[i + 1] = (j + 1) % vertices.Length;



            triangles[i + 2] = (j + 3) % vertices.Length;



 



            triangles[i + 3] = j;



            triangles[i + 4] = (j + 3) % vertices.Length;



            triangles[i + 5] = (j + 2) % vertices.Length;



        }



 



        Mesh mesh = GetComponent<MeshFilter>().mesh;



        mesh.Clear();



 



        mesh.vertices = vertices;



        mesh.triangles = triangles;



    }



    #endregion

一样，代码做点小的改动就能产生太阳和锯齿的图片，如下：

、

怎么改的上面看明白的一眼就看出来了，哈哈，你们自己写吧。

五：完整代码

本篇博客涉及的脚本的完整代码如下：





using UnityEngine;




using System.Collections;



 




public enum PlaneState



{



    Triangle,



    Square,



    Circle,



    Ring



}



 




public class Test : MonoBehaviour




{



 



    public Material mat;



 



    public PlaneState planeState;



 



    // Use this for initialization




    void Start()




    {



 



        switch (planeState)



        {



            case PlaneState.Triangle:



                DrawTriangle();



                break;



            case PlaneState.Square:



                DrawSquare();



                break;



            case PlaneState.Circle:



                DrawCircle(2, 50, Vector3.zero);



                break;



            case PlaneState.Ring:



                DrawRing(2, 3, 50, Vector3.zero);



                break;



        }



 



 



 



    }



 



    #region 画三角形




    void DrawTriangle()




    {



        gameObject.AddComponent<MeshFilter>();



        gameObject.AddComponent<MeshRenderer>();



        gameObject.GetComponent<MeshRenderer>().material = mat;



 



        Mesh mesh = GetComponent<MeshFilter>().mesh;



        mesh.Clear();



 



        //设置顶点




        mesh.vertices = new Vector3[] { new Vector3(0, 0, 0), new Vector3(0, 1, 0), new Vector3(1, 1, 0) };



        //设置三角形顶点顺序，顺时针设置




        mesh.triangles = new int[] { 0, 1, 2 };



    }



    #endregion




 



    #region 画正方形




    void DrawSquare()




    {



        gameObject.AddComponent<MeshFilter>();



        gameObject.AddComponent<MeshRenderer>();



        gameObject.GetComponent<MeshRenderer>().material = mat;



 



        Mesh mesh = GetComponent<MeshFilter>().mesh;



        mesh.Clear();



 



        mesh.vertices = new Vector3[] { new Vector3(0, 0, 0), new Vector3(0, 1, 0), new Vector3(1, 1, 0), new Vector3(1, 0, 0) };



        mesh.triangles = new int[]



        { 0, 1, 2,



          0, 2, 3




        };



    }



    #endregion




 



    #region 画圆




    /// <summary>




    /// 画圆




    /// </summary>




    /// <param name="radius">圆的半径</param>




    /// <param name="segments">圆的分割数</param>




    /// <param name="centerCircle">圆心得位置</param>




    void DrawCircle(float radius, int segments, Vector3 centerCircle)




    {



        gameObject.AddComponent<MeshFilter>();



        gameObject.AddComponent<MeshRenderer>();



        gameObject.GetComponent<MeshRenderer>().material = mat;



 



        //顶点




        Vector3[] vertices = new Vector3[segments + 1];



        vertices[0] = centerCircle;



        float deltaAngle = Mathf.Deg2Rad * 360f / segments;



        float currentAngle = 0;



        for (int i = 1; i < vertices.Length; i++)



        {



            float cosA = Mathf.Cos(currentAngle);



            float sinA = Mathf.Sin(currentAngle);



            vertices[i] = new Vector3(cosA * radius + centerCircle.x, sinA * radius + centerCircle.y, 0);



            currentAngle += deltaAngle;



        }



 



        //三角形




        int[] triangles = new int[segments * 3];



        for (int i = 0, j = 1; i < segments * 3 - 3; i += 3, j++)



        {



            triangles[i] = 0;



            triangles[i + 1] = j + 1;



            triangles[i + 2] = j;



        }



        triangles[segments * 3 - 3] = 0;



        triangles[segments * 3 - 2] = 1;



        triangles[segments * 3 - 1] = segments;



 



 



        Mesh mesh = GetComponent<MeshFilter>().mesh;



        mesh.Clear();



 



        mesh.vertices = vertices;



        mesh.triangles = triangles;



    }



    #endregion




 



    #region 画圆环




    /// <summary>




    /// 画圆环




    /// </summary>




    /// <param name="radius">圆半径</param>




    /// <param name="innerRadius">内圆半径</param>




    /// <param name="segments">圆的分个数</param>




    /// <param name="centerCircle">圆心坐标</param>




    void DrawRing(float radius, float innerRadius, int segments, Vector3 centerCircle)




    {



        gameObject.AddComponent<MeshFilter>();



        gameObject.AddComponent<MeshRenderer>();



        gameObject.GetComponent<MeshRenderer>().material = mat;



 



        //顶点




        Vector3[] vertices = new Vector3[segments * 2];



        float deltaAngle = Mathf.Deg2Rad * 360f / segments;



        float currentAngle = 0;



        for (int i = 0; i < vertices.Length; i += 2)



        {



            float cosA = Mathf.Cos(currentAngle);



            float sinA = Mathf.Sin(currentAngle);



            vertices[i] = new Vector3(cosA * innerRadius + centerCircle.x, sinA * innerRadius + centerCircle.y, 0);



            vertices[i + 1] = new Vector3(cosA * radius + centerCircle.x, sinA * radius + centerCircle.y, 0);



            currentAngle += deltaAngle;



        }



 



        //三角形




        int[] triangles = new int[segments * 6];



        for (int i = 0, j = 0; i < segments * 6; i += 6, j += 2)



        {



            triangles[i] = j;



            triangles[i + 1] = (j + 1) % vertices.Length;



            triangles[i + 2] = (j + 3) % vertices.Length;



 



            triangles[i + 3] = j;



            triangles[i + 4] = (j + 3) % vertices.Length;



            triangles[i + 5] = (j + 2) % vertices.Length;



        }



 



        Mesh mesh = GetComponent<MeshFilter>().mesh;



        mesh.Clear();



 



        mesh.vertices = vertices;



        mesh.triangles = triangles;



    }



    #endregion




}

欢迎多多指教！

Mesh编程基础

一.画三角形

二.画正方形

三.画圆

四.画圆环

五：完整代码

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