写一个unity按照给定法线方向生成半球体mesh的脚本

可以使用以下脚本实现：

using UnityEngine;

public class HalfSphereMeshGenerator : MonoBehaviour
{
    [SerializeField] private int numLongitudeSections = 10;
    [SerializeField] private int numLatitudeSections = 10;
    [SerializeField] private float radius = 1f;
    [SerializeField] private Vector3 upDirection = Vector3.up;

    private void Start()
    {
        Mesh mesh = new Mesh();

        Vector3[] vertices = new Vector3[numLongitudeSections * (numLatitudeSections + 1)];
        int[] triangles = new int[numLongitudeSections * numLatitudeSections * 6];
        
        for (int lat = 0; lat <= numLatitudeSections; lat++)
        {
            float theta = lat * Mathf.PI / numLatitudeSections;
            float sinTheta = Mathf.Sin(theta);
            float cosTheta = Mathf.Cos(theta);

            for (int lon = 0; lon < numLongitudeSections; lon++)
            {
                float phi = lon * 2f * Mathf.PI / numLongitudeSections;
                float sinPhi = Mathf.Sin(phi);
                float cosPhi = Mathf.Cos(phi);

                Vector3 direction = new Vector3(sinTheta * cosPhi, cosTheta, sinTheta * sinPhi);

                Vector3 normal = Quaternion.FromToRotation(upDirection, direction) * upDirection;

                vertices[lat * numLongitudeSections + lon] = normal * radius;
            }
        }

        int index = 0;

        for (int lat = 0; lat < numLatitudeSections; lat++)
        {
            for (int lon = 0; lon < numLongitudeSections; lon++)
            {
                int first = lat * numLongitudeSections + lon;
                int second = first + numLongitudeSections;

                triangles[index++] = first;
                triangles[index++] = second + 1;
                triangles[index++] = second;

                triangles[index++] = first;
                triangles[index++] = first + 1;
                triangles[index++] = second + 1;
            }
        }

        mesh.vertices = vertices;
        mesh.triangles = triangles;
        mesh.RecalculateNormals();

        GetComponent<MeshFilter>().mesh = mesh;
    }
}

这个脚本使用给定法线方向和半径，按照给定的经度和纬度划分数量，生成半球体的网格。您可以将它附加到一个 GameObject 上，然后通过检查器中的参数进行自定义设置。