我目前有一个“CreateMesh”脚本，可以将其作为具有网格渲染器和网格过滤器的对象的组件，并且使用多边形碰撞器在网格尺寸中创建一个 2D 网格，给定“MeshType”变量设置为“tri”或“box”(分别用于三角形和矩形网格。)我还想添加创建圆形网格的功能，但是从一些研究中我意识到这并不那么简单正如我首先想到的。然而我还没有找到任何有帮助的东西。
这是我用于盒子和三角形网格的代码:
public float width = 5f;
public float height = 5f;
public string meshType;
public PolygonCollider2D polyCollider;
void Start()
{
polyCollider = GetComponent<PolygonCollider2D>();
}
// Update is called once per frame
void Update () {
if (meshType == "tri")
{
TriangleMesh(width, height);
}
if (meshType == "box")
{
BoxMesh(width, height);
}
}
void TriangleMesh(float width, float height)
{
MeshFilter mf = GetComponent<MeshFilter>();
Mesh mesh = new Mesh();
mf.mesh = mesh;
//Verticies
Vector3[] verticies = new Vector3[3]
{
new Vector3(0,0,0), new Vector3(width, 0, 0), new Vector3(0, height, 0)
};
//Triangles
int[] tri = new int[3];
tri[0] = 0;
tri[1] = 2;
tri[2] = 1;
//normals
Vector3[] normals = new Vector3[3];
normals[0] = -Vector3.forward;
normals[1] = -Vector3.forward;
normals[2] = -Vector3.forward;
//UVs
Vector2[] uv = new Vector2[3];
uv[0] = new Vector2(0, 0);
uv[0] = new Vector2(1, 0);
uv[0] = new Vector2(0, 1);
//initialise
mesh.vertices = verticies;
mesh.triangles = tri;
mesh.normals = normals;
mesh.uv = uv;
//setting up collider
polyCollider.pathCount = 1;
Vector2[] path = new Vector2[3]
{
new Vector2(0,0), new Vector2(0, height), new Vector2(width, 0)
};
polyCollider.SetPath(0, path);
}
void BoxMesh(float width, float height)
{
MeshFilter mf = GetComponent<MeshFilter>();
Mesh mesh = new Mesh();
mf.mesh = mesh;
//Verticies
Vector3[] verticies = new Vector3[4]
{
new Vector3(0,0,0), new Vector3(0, height, 0), new Vector3(width, height, 0), new Vector3(width, 0, 0)
};
//Triangles
int[] tri = new int[6];
tri[0] = 0;
tri[1] = 1;
tri[2] = 3;
tri[3] = 1;
tri[4] = 2;
tri[5] = 3;
//normals
Vector3[] normals = new Vector3[4];
normals[0] = -Vector3.forward;
normals[1] = -Vector3.forward;
normals[2] = -Vector3.forward;
normals[3] = -Vector3.forward;
//UVs
Vector2[] uv = new Vector2[4];
uv[0] = new Vector2(0, 0);
uv[1] = new Vector2(0, 1);
uv[2] = new Vector2(1, 1);
uv[3] = new Vector2(1, 0);
//initialise
mesh.vertices = verticies;
mesh.triangles = tri;
mesh.normals = normals;
mesh.uv = uv;
//setting up collider
polyCollider.pathCount = 1;
Vector2[] path = new Vector2[4]
{
new Vector2(0,0), new Vector2(0, height), new Vector2(width, height), new Vector2(width, 0)
};
polyCollider.SetPath(0, path);
}
所以本质上我想要一个可以在更新方法中调用的函数，它可以简单地创建一个圆形网格。例如:
void Update () {
if (meshType == "tri")
{
TriangleMesh(width, height);
}
if (meshType == "box")
{
BoxMesh(width, height);
}
if (meshType == "circle")
{
CircleMesh(radius);
}
}
最佳答案
我设法找到的解决方案涉及创建一个 n 边且 n 值较大的正多边形。我有一个名为 PolyMesh 的函数，它创建一个具有 n 条边和给定半径的正多边形网格。
生成顶点
对于 n 边正多边形的每个顶点，相对于多边形中心的坐标由以下公式给出:x = r*i*sin(θ) 和 y = r* i*cos(θ) 因此，x = r*i*sin(2π/2) 和 y = r*i*cos(2π/2) >。其中 i 从 0 迭代到 n-1。因此，我们可以拥有一个分配有顶点的列表，然后将其转换为数组:
//verticies
List<Vector3> verticiesList = new List<Vector3> { };
float x;
float y;
for (int i = 0; i < n; i ++)
{
x = radius * Mathf.Sin((2 * Mathf.PI * i) / n);
y = radius * Mathf.Cos((2 * Mathf.PI * i) / n);
verticiesList.Add(new Vector3(x, y, 0f));
}
Vector3[] verticies = verticiesList.ToArray();
生成三角形
给定的 n 边正多边形可以从同一点分割成 n-2 个三角形。所以我们可以如下生成每个三角形:
//triangles
List<int> trianglesList = new List<int> { };
for(int i = 0; i < (n-2); i++)
{
trianglesList.Add(0);
trianglesList.Add(i+1);
trianglesList.Add(i+2);
}
int[] triangles = trianglesList.ToArray();
生成法线
由于这是一个 2d 对象，我们可以将每个法线设置为 -Vector3.forward，如下所示:
//normals
List<Vector3> normalsList = new List<Vector3> { };
for (int i = 0; i < verticies.Length; i++)
{
normalsList.Add(-Vector3.forward);
}
Vector3[] normals = normalsList.ToArray();
生成碰撞器
我们可以只使用具有相同半径的圆形碰撞器，但为了使该函数适用于 n 值较小的多边形，我们必须使用 PolygonCollider2D。由于顶点已经在顶点数组中按顺序排列，我们可以简单地将它们用作 PolygonCollider2D 的路径。
//polyCollider
polyCollider.pathCount = 1;
List<Vector2> pathList = new List<Vector2> { };
for (int i = 0; i < n; i++)
{
pathList.Add(new Vector2(verticies[i].x, verticies[i].y));
}
Vector2[] path = pathList.ToArray();
polyCollider.SetPath(0, path);
完整的代码应如下所示:
public PolygonCollider2D polyCollider;
void Start()
{
polyCollider = GetComponent<PolygonCollider2D>();
}
void PolyMesh(float radius, int n)
{
MeshFilter mf = GetComponent<MeshFilter>();
Mesh mesh = new Mesh();
mf.mesh = mesh;
//verticies
List<Vector3> verticiesList = new List<Vector3> { };
float x;
float y;
for (int i = 0; i < n; i ++)
{
x = radius * Mathf.Sin((2 * Mathf.PI * i) / n);
y = radius * Mathf.Cos((2 * Mathf.PI * i) / n);
verticiesList.Add(new Vector3(x, y, 0f));
}
Vector3[] verticies = verticiesList.ToArray();
//triangles
List<int> trianglesList = new List<int> { };
for(int i = 0; i < (n-2); i++)
{
trianglesList.Add(0);
trianglesList.Add(i+1);
trianglesList.Add(i+2);
}
int[] triangles = trianglesList.ToArray();
//normals
List<Vector3> normalsList = new List<Vector3> { };
for (int i = 0; i < verticies.Length; i++)
{
normalsList.Add(-Vector3.forward);
}
Vector3[] normals = normalsList.ToArray();
//initialise
mesh.vertices = verticies;
mesh.triangles = triangles;
mesh.normals = normals;
//polyCollider
polyCollider.pathCount = 1;
List<Vector2> pathList = new List<Vector2> { };
for (int i = 0; i < n; i++)
{
pathList.Add(new Vector2(verticies[i].x, verticies[i].y));
}
Vector2[] path = pathList.ToArray();
polyCollider.SetPath(0, path);
}
关于c# - 在 Unity 中创建 2D 圆形网格，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/50606756/