本文章主要工作是六边形网格的绘制，可以用来制作地图功能。
先来看一下这样的图：
image
image.gif
如图所示。六边形有6个方向，6个顶点，同时定义中心点到边的最短距离为内径innerRadius，定义中心点到顶点的距离为外径outerRadius。
六边形可以拆分为6个等边三角形，所以很容易得出：
image
image.gif
定义游戏中六边形的边长(即外径)为1
HexMetrics类代码实现：
public static class HexMetrics{
/// <summary>
/// 外径，中心到顶点距离
/// </summary>
public const float outerRadius = 10f;
/// <summary>
/// 内径，中心到边距离，0.866025404为二分之根号三的近似值
/// </summary>
//Mathf.Sin(60) = 0.866025404;
public const float innerRadius = outerRadius * 0.866025404f;
/// <summary>
/// 六边形的六个顶点坐标
/// </summary>
public static readonly Vector3[] corners = {
new Vector3(0f, 0f, outerRadius),
new Vector3(innerRadius,0f,0.5f*outerRadius),
new Vector3(innerRadius,0f,-0.5f*outerRadius),
new Vector3(0f,0f,-outerRadius),
new Vector3(-innerRadius,0f,-0.5f*outerRadius),
new Vector3(-innerRadius,0f,0.5f*outerRadius),
new Vector3(0f, 0f, outerRadius),
};}
绘制三角形的时候代码:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public enum HexDirection{
NE, E, SE, SW, W, NW,
}
[RequireComponent(typeof(MeshFilter), typeof(MeshRenderer), typeof(MeshCollider))]
public class HexCell : MonoBehaviour{
private Mesh mesh;
private List<Vector3> vertices;
private List<int> triangles;
private void Awake() {
GetComponent<MeshFilter>().mesh = mesh = GetComponent<MeshCollider>().sharedMesh = new Mesh(); GetComponent<MeshCollider>().convex = true;
mesh.name = "Hex Cell";
vertices = new List<Vector3>();
triangles = new List<int>();
Draw();
}
// Use this for initialization
void Start() { }
// Update is called once per frame
void Update() { }
/// <summary>
/// 绘制地形
/// </summary>
public void Draw() {
Clear();
Vector3 center = Vector3.zero;
for (HexDirection dir = HexDirection.NE; dir <= HexDirection.NW; dir++) {
AddTriangle(center, HexMetrics.corners[(int)dir], HexMetrics.corners[(int)dir + 1]);
}
UpdateMesh();
}
/// <summary> /// 清空mesh数据 /// </summary>
private void Clear() {
mesh.Clear();
vertices.Clear();
triangles.Clear();
}
/// <summary> /// 绘制mesh数据 /// </summary>
private void UpdateMesh() {
mesh.vertices = vertices.ToArray();
mesh.triangles = triangles.ToArray();
mesh.RecalculateNormals();
mesh.RecalculateBounds();
}
/// <summary> /// 添加三角形。 /// </summary> /// <param name="v1"></param> /// <param name="v2"></param> /// <param name="v3"></param>
private void AddTriangle(Vector3 v1, Vector3 v2, Vector3 v3) {
int count = triangles.Count;
vertices.Add(v1);
triangles.Add(count++);
vertices.Add(v2);
triangles.Add(count++);
vertices.Add(v3);
triangles.Add(count++);
}}
在unity中随便挂在一个空对象上。就可以生成如下图：
image
image.gif
接下来是构建地图网格：
image
image.gif
从上图可以看出来如下规律：
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1.同一行的相邻六边形的间距为2个内径的距离
2.两列六边形，在纵坐标上相差1.5个外径的距离
3.列数为奇数的六边形在横坐标上，会向右偏移1个内径的距离。
所以我们可以通过如下方式将队列上的坐标(x,y)转换为空间上的坐标：
private Vector3 GetPos(int x, int y) {
float posX = x;
float posY = y;
if ((y & 1) != 0) {
posX += 0.5f;
}
Vector3 pos = new Vector3(2f * posX * HexMetrics.innerRadius, 0f, 1.5f * posY * HexMetrics.outerRadius);
return pos; }
|
最后完整代码：
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Train : MonoBehaviour {
public int col = 10;
public int row = 10;
private Vector3 GetPos(int x, int y) {
float posX = x;
float posY = y;
if ((y & 1) != 0) {
posX += 0.5f;
}
Vector3 pos = new Vector3(2f * posX * HexMetrics.innerRadius, 0f, 1.5f * posY * HexMetrics.outerRadius);
return pos;
}
// Use this for initialization
void Start () {
for (int i = 0; i < col; i++) {
for (int j = 0; j < row; j++) {
Vector3 pos = GetPos(i, j);
GameObject Plane = GameObject.CreatePrimitive(PrimitiveType.Plane);
Plane.AddComponent<HexCell>();
Plane.transform.position = pos;
Plane.GetComponent<MeshRenderer>().material.color = new Color(i / col, (i + j) / (col + row), j / row);
}
} }}
运行一下，我们就可以得到下面图片：
image
image.gif
