該文件只限于畫(huà)2D的圖形,在模仿Paper.io這個(gè)游戲時(shí),遇到的問(wèn)題,記錄下,以供下次參考.
關(guān)于Unity中的網(wǎng)格過(guò)濾器,和網(wǎng)格渲染器,可以參考Unity的手冊(cè)文檔(請(qǐng)看文章最后).
這里簡(jiǎn)單說(shuō)下我在模仿paper這個(gè)游戲的思路.
玩家在移動(dòng)的過(guò)程中,會(huì)不斷的更新位置,所以需要記錄下玩家的點(diǎn).并畫(huà)在屏幕上,可以用Mesh Renderer,和Mesh Filter組件來(lái)渲染,然后初始化一個(gè)mesh對(duì)象,將其設(shè)置給Mesh Filter的相關(guān)屬性.這個(gè)mesh就是負(fù)責(zé)畫(huà)圖的內(nèi)容,他需要圖形的頂點(diǎn)坐標(biāo),和三角形的順序,而如果頂點(diǎn)數(shù)據(jù)復(fù)雜,計(jì)算三角形的順序,就會(huì)變得繁瑣,這個(gè)Triangulator剛好將這個(gè)過(guò)程封裝了.只要給他傳入一個(gè)頂點(diǎn)坐標(biāo)數(shù)組,就能直接生成mesh需要的三角形數(shù)組出來(lái),然后將頂點(diǎn)坐標(biāo),和三角形數(shù)組設(shè)置給mesh,即可顯示我們需要的圖形出來(lái).
這里有個(gè)簡(jiǎn)單示例

void Start () {
        List<Vector2> vectors = new List<Vector2> ();

        vectors.Add (new Vector2 (0, 0));
        vectors.Add (new Vector2 (10, 0));
        vectors.Add (new Vector2 (10, 20));
        vectors.Add (new Vector2 (20, 20));
        vectors.Add (new Vector2 (20, 30));
        vectors.Add (new Vector2 (10, 30));
        vectors.Add (new Vector2 (0, 20));

        // Use the triangulator to get indices for creating triangles
        Triangulator tr = new Triangulator(vectors.ToArray());
        int[] indices = tr.Triangulate();

        // Create the Vector3 vertices
        Vector3[] vertices = new Vector3[vectors.Count];
        for (int i=0; i<vertices.Length; i++) {
            vertices[i] = new Vector3(vectors[i].x, vectors[i].y, 0);
        }

        // Create the mesh
        Mesh msh = new Mesh();
        msh.vertices = vertices;
        msh.triangles = indices;
        msh.RecalculateNormals();
        msh.RecalculateBounds();

        // Set up game object with mesh;
        gameObject.AddComponent(typeof(MeshRenderer));

        MeshFilter filter = gameObject.GetComponent<MeshFilter> ();
        if (filter == null) {
            filter = gameObject.AddComponent<MeshFilter>();
        }
        filter.mesh = msh;

    }

生成的內(nèi)容就是這個(gè)樣子

以下為Triangulator的完整代碼

using UnityEngine;
using System.Collections.Generic;

public class Triangulator
{
    private List<Vector2> m_points = new List<Vector2>();

    public Triangulator (Vector2[] points) {
        m_points = new List<Vector2>(points);
    }

    public int[] Triangulate() {
        List<int> indices = new List<int>();

        int n = m_points.Count;
        if (n < 3)
            return indices.ToArray();

        int[] V = new int[n];
        if (Area() > 0) {
            for (int v = 0; v < n; v++)
                V[v] = v;
        }
        else {
            for (int v = 0; v < n; v++)
                V[v] = (n - 1) - v;
        }

        int nv = n;
        int count = 2 * nv;
        for (int m = 0, v = nv - 1; nv > 2; ) {
            if ((count--) <= 0)
                return indices.ToArray();

            int u = v;
            if (nv <= u)
                u = 0;
            v = u + 1;
            if (nv <= v)
                v = 0;
            int w = v + 1;
            if (nv <= w)
                w = 0;

            if (Snip(u, v, w, nv, V)) {
                int a, b, c, s, t;
                a = V[u];
                b = V[v];
                c = V[w];
                indices.Add(a);
                indices.Add(b);
                indices.Add(c);
                m++;
                for (s = v, t = v + 1; t < nv; s++, t++)
                    V[s] = V[t];
                nv--;
                count = 2 * nv;
            }
        }

        indices.Reverse();
        return indices.ToArray();
    }

    private float Area () {
        int n = m_points.Count;
        float A = 0.0f;
        for (int p = n - 1, q = 0; q < n; p = q++) {
            Vector2 pval = m_points[p];
            Vector2 qval = m_points[q];
            A += pval.x * qval.y - qval.x * pval.y;
        }
        return (A * 0.5f);
    }

    private bool Snip (int u, int v, int w, int n, int[] V) {
        int p;
        Vector2 A = m_points[V[u]];
        Vector2 B = m_points[V[v]];
        Vector2 C = m_points[V[w]];
        if (Mathf.Epsilon > (((B.x - A.x) * (C.y - A.y)) - ((B.y - A.y) * (C.x - A.x))))
            return false;
        for (p = 0; p < n; p++) {
            if ((p == u) || (p == v) || (p == w))
                continue;
            Vector2 P = m_points[V[p]];
            if (InsideTriangle(A, B, C, P))
                return false;
        }
        return true;
    }

    private bool InsideTriangle (Vector2 A, Vector2 B, Vector2 C, Vector2 P) {
        float ax, ay, bx, by, cx, cy, apx, apy, bpx, bpy, cpx, cpy;
        float cCROSSap, bCROSScp, aCROSSbp;

        ax = C.x - B.x; ay = C.y - B.y;
        bx = A.x - C.x; by = A.y - C.y;
        cx = B.x - A.x; cy = B.y - A.y;
        apx = P.x - A.x; apy = P.y - A.y;
        bpx = P.x - B.x; bpy = P.y - B.y;
        cpx = P.x - C.x; cpy = P.y - C.y;

        aCROSSbp = ax * bpy - ay * bpx;
        cCROSSap = cx * apy - cy * apx;
        bCROSScp = bx * cpy - by * cpx;

        return ((aCROSSbp >= 0.0f) && (bCROSScp >= 0.0f) && (cCROSSap >= 0.0f));
    }
}

參考資料:
http://wiki.unity3d.com/index.php?title=Triangulator
https://docs.unity3d.com/ScriptReference/Mesh.html