Unity动态构建Mesh来绘制任意多边形（雷达图效果）由于很多同学没有做出来，特此补传⼀个Demo⼯程 (版本Unity2019.1.8f1)
使⽤场景
雷达图
原理
就是动态new⼀个Mesh，设置三⾓形和定点数据，然后赋值给MeshFilter，通过MeshRenderer绘制出来
步骤
1 把⽂章下⾯的脚本复制到⼯程中
2 在场景中创建⼀个空物体，命名为Mesh，挂上PolygonDrawer组件
3 在Mesh物体下创建N个Sphere
4 创建⼀个材质球，选择你需要的shader，⽐如下⽂⽤的是Unlit/Color，并且调整了颜⾊为蓝⾊
5 把材质球赋值给PolygonDrawer组件
6 把N个Sphere赋值给PolygonDrawer组件（注意N个Sphere的摆放，本⽂章的脚本只⽀持顺时针或者逆时针顺序）
7 运⾏Unity，注意要运⾏了才能看到动态构建出来的多边形Mesh效果
补充
评论区有同学说有问题，我⽤Unity5.x、Unity2017和Unity2019都试过了，都可以正常显⽰的效果如下
代码
MethodExtensionForUnity.cs
using UnityEngine;
//Unity的⼀些扩展⽅法
static public class MethodExtensionForUnity
{
/// <summary>
/// Gets or add a component. Usage example:
/// BoxCollider boxCollider = transform.GetOrAddComponent<BoxCollider>();
/// </summary>
static public T GetOrAddComponent<T>(this Component child, bool t_enable = fal) where T : Component {
T result = child.GetComponent<T>();
if (result == null)
{
result = child.gameObject.AddComponent<T>();
}
var bcomp = result as Behaviour;
if (t_enable)
{
if (bcomp != null) abled = true;
}
return result;
}
函数周期公式static public T GetOrAddComponent<T>(this GameObject go) where T : Component
{
T result = go.transform.GetComponent<T>();
if (result == null)
{
result = go.AddComponent<T>();
}
var bcomp = result as Behaviour;
if (bcomp != null) abled = true;
return result;
英语学校}
public static void walk(this GameObject o, System.Action<GameObject> f)
{
f(o);
int numChildren = o.transform.childCount;
for (int i = 0; i < numChildren; ++i)
{
ansform.GetChild(i).gameObject, f);
}
}
}
Triangulator.cs
using UnityEngine;
using System.Collections.Generic;
public class Triangulator
{
private List<Vector2> m_points = new List<Vector2>();
public Triangulator (Vector2[] points) {
public Triangulator (Vector2[] points) {
m_points = new List<Vector2>(points); }祈谷坛
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;
}
el {
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.Rever();
return indices.ToArray();
自重自省自警自励
}
private float Area () {
int n = m_points.Count;
海报素材背景
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);
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 fal;
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 fal;
}
return true;
}
便宜平板电脑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;
左丘
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;
工作英语return ((aCROSSbp >= 0.0f) && (bCROSScp >= 0.0f) && (cCROSSap >= 0.0f)); }
}
PolygonDrawer.cs
