Mesh

简介

所有图形都是三角形组成的，绘制包括三部分

vertices：图形的所有顶点坐标
triangles：图形的绘制顺序，选三个顶点组成一个三角形，顺序必须顺时针，逆时针会绘制在背面
uv：材质的贴图要和图形对应，uv左下角(0,0)，右上角(1,1)，就是将每一个顶点坐标对应到贴图上，可先将顶点坐标移至正右上角区域，然后进行比例缩放到1

实例

三角形正方形

    //3
    Vector3[] v_3 = new Vector3[] {
        new Vector3(1, 1, 0),
        new Vector3(0, 0, 0),
        new Vector3(0, 1, 0)
    };

    int[] t_3 = new int[] {
        0,1,2
    };

    Vector2[] uv_3 = new Vector2[] {
        new Vector2(1,1),
        new Vector2(0,0),
        new Vector2(0,1),
    };

    //4
    Vector3[] v_4 = new Vector3[] {
        new Vector3(1, 1, 0),
        new Vector3(1, 0, 0),
        new Vector3(0, 0, 0),
        new Vector3(0, 1, 0)
    };

    int[] t_4 = new int[] {
        0,2,3,
        1,2,3
    };

    Vector2[] uv_4 = new Vector2[] {
        new Vector2(1,1),
        new Vector2(1,0),
        new Vector2(0,0),
        new Vector2(0,1),
    };

    void Start()
    {
        Creater("obj3", v_3, t_3, uv_3, Mat.Green);
        Creater("obj4", v_4, t_4, uv_4, Mat.Red);
    }
    
     void Creater(string name, Vector3[] ver, int[] tri, Vector2[] uv, Mat mat)
    {
        GameObject obj = new GameObject();
        obj.name = name;
        obj.transform.localPosition = Vector3.zero;
        obj.transform.localScale = Vector3.one;
        obj.transform.localRotation = Quaternion.identity;

        obj.AddComponent();
        Mesh mesh = obj.GetComponent().mesh;
        mesh.Clear();

        mesh.vertices = ver;
        mesh.triangles = tri;

        obj.AddComponent();
        obj.GetComponent().material = mats[(int)mat];
        mesh.uv = uv;
    }

圆形，由圆心与圆上点组成三角形


    void CreateCircle(Vector2 center, float r, int num)
    {
        GameObject obj = new GameObject();
        obj.name = "circle";
        obj.transform.localPosition = CreatePos * CreateNum;
        obj.transform.localScale = Vector3.one;
        obj.transform.localRotation = Quaternion.identity;
        CreateNum += 1;

        obj.AddComponent();
        Mesh mesh = obj.GetComponent().mesh;
        mesh.Clear();

        Vector3[] ver = new Vector3[num + 1];
        int[] tri = new int[3 * num];
        Vector2[] uv = new Vector2[num + 1];

        float deltaAngle = 360 / num;
        ver[num] = (Vector3)center;

        for (int i = 0; i < num; i++)
        {
            float angle = (90 - i * deltaAngle) * Mathf.Deg2Rad;
            ver[i] = new Vector3(r * Mathf.Cos(angle) + center.x, r * Mathf.Sin(angle) + center.y, 0);

            tri[i * 3] = i;
            if (i == num - 1) tri[i * 3 + 1] = 0;
            else tri[i * 3 + 1] = i + 1;
            tri[i * 3 + 2] = num;
        }
        mesh.vertices = ver;
        mesh.triangles = tri;

        obj.AddComponent();
        obj.GetComponent().material = mats[1];
        for (int i = 0; i < ver.Length; i++)
        {
            uv[i] = new Vector2(ver[i].x - center.x + r, ver[i].y - center.y + r)/2/r;
        }
        mesh.uv = uv;
    }

电风扇型

    void CreateCircle1(Vector2 center, float r, int num)
    {
        GameObject obj = new GameObject();
        obj.name = "circle1";
        obj.transform.localPosition = CreatePos * CreateNum;
        obj.transform.localScale = Vector3.one;
        obj.transform.localRotation = Quaternion.identity;
        CreateNum += 1;

        obj.AddComponent();
        Mesh mesh = obj.GetComponent().mesh;
        mesh.Clear();

        Vector3[] ver = new Vector3[num + 1];
        int[] tri = new int[3 * num];
        Vector2[] uv = new Vector2[num + 1];

        float deltaAngle = 360 / num;
        ver[num] = (Vector3)center;

        for (int i = 0; i < num; i++)
        {
            float angle = (90 - i * deltaAngle) * Mathf.Deg2Rad;
            ver[i] = new Vector3(r * Mathf.Cos(angle) + center.x, r * Mathf.Sin(angle) + center.y, 0);

            if (i % 2 == 1)
            {
                tri[i * 3] = num;
                tri[i * 3 + 1] = num;
                tri[i * 3 + 2] = num;
            }
            else
            {
                tri[i * 3] = i;
                if (i == num - 1) tri[i * 3 + 1] = 0;
                else tri[i * 3 + 1] = i + 1;
                tri[i * 3 + 2] = num;
            }
        }

        mesh.vertices = ver;
        mesh.triangles = tri;

        obj.AddComponent();
        obj.GetComponent().material = mats[1];
        for (int i = 0; i < ver.Length; i++)
        {
            uv[i] = new Vector2(ver[i].x - center.x + r, ver[i].y - center.y + r) / 2 / r;
        }
        mesh.uv = uv;
    }

圆环，有一个个小梯形组成，每个梯形又可以由两个三角形组成

    void CreateCircle2(Vector2 center, float r1, float r2, int num)
    {
        GameObject obj = new GameObject();
        obj.name = "circle2";
        obj.transform.localPosition = CreatePos * CreateNum;
        obj.transform.localScale = Vector3.one;
        obj.transform.localRotation = Quaternion.identity;
        CreateNum += 1;

        obj.AddComponent();
        Mesh mesh = obj.GetComponent().mesh;
        mesh.Clear();

        Vector3[] ver = new Vector3[num * 2];
        int[] tri = new int[3 * num * 2];
        Vector2[] uv = new Vector2[num * 2];

        float deltaAngle = 360 / num;

        for (int i = 0; i < num; i++)
        {
            float angle = (90 - i * deltaAngle) * Mathf.Deg2Rad;
            ver[i] = new Vector3(r1 * Mathf.Cos(angle) + center.x, r1 * Mathf.Sin(angle) + center.y, 0);
            ver[i + num] = new Vector3(r2 * Mathf.Cos(angle) + center.x, r2 * Mathf.Sin(angle) + center.y, 0);

            //连接处
            if (i == num - 1)
            {
                tri[i * 3 * 2] = i;
                tri[i * 3 * 2 + 1] = 0;
                tri[i * 3 * 2 + 2] = num;
                tri[i * 3 * 2 + 3] = i;
                tri[i * 3 * 2 + 4] = num;
                tri[i * 3 * 2 + 5] = i + num;
            }
            else
            {
                tri[i * 3 * 2] = i;
                tri[i * 3 * 2 + 1] = i + 1;
                tri[i * 3 * 2 + 2] = i + 1 + num;
                tri[i * 3 * 2 + 3] = i;
                tri[i * 3 * 2 + 4] = i + 1 + num;
                tri[i * 3 * 2 + 5] = i + num;
            }
        }
        mesh.vertices = ver;
        mesh.triangles = tri;

        obj.AddComponent();
        obj.GetComponent().material = mats[1];
        for (int i = 0; i < ver.Length; i++)
        {
            uv[i] = new Vector2(ver[i].x - center.x + r1, ver[i].y - center.y + r1) / 2 / r1;
        }
        mesh.uv = uv;
    }

圆弧形

    void Creater(float r1, float r2, float angle)
    {
        GameObject obj = new GameObject();
        obj.transform.parent = gameObject.transform;
        obj.transform.localPosition = Vector3.zero;
        obj.transform.localScale = Vector3.one;
        obj.transform.localRotation = Quaternion.identity;

        obj.AddComponent();
        Mesh mesh = obj.GetComponent().mesh;
        mesh.Clear();

        //默认一圈分割成60份，6度一份
        float deltaAngle = 6;

        int num = Mathf.CeilToInt(angle * 2 / 2 / deltaAngle) + 1;  //5
        Vector3[] ver = new Vector3[num * 2]; //10
        int[] tri = new int[(num - 1) * 2 * 3];
        for (int i = 0; i < num; i++)
        {
            float rad = (i * deltaAngle - angle / 2) * Mathf.Deg2Rad;
            ver[i] = new Vector3(r1 * Mathf.Cos(rad), 0, r1 * Mathf.Sin(rad));
            ver[i + num] = new Vector3(r2 * Mathf.Cos(rad), 0, r2 * Mathf.Sin(rad));
            if (i == num - 1)
            {
                continue;
            }
            else
            {
                tri[i * 3 * 2] = i + 1 + num;
                tri[i * 3 * 2 + 1] = i + 1;
                tri[i * 3 * 2 + 2] = i;
                tri[i * 3 * 2 + 3] = i + num;
                tri[i * 3 * 2 + 4] = i + 1 + num;
                tri[i * 3 * 2 + 5] = i;
            }
        }

        mesh.vertices = ver;
        mesh.triangles = tri;

        Material material = new Material(Shader.Find("Diffuse"));
        material.SetColor("_Color", Color.white);
        obj.AddComponent();
        obj.GetComponent().material = material;

        obj.AddComponent();
    }

Mesh

简介

实例

总结

参考

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