在3D中，我们可以通过在Bezier曲线上添加法线来使曲线看起来更加真实。下面是一些示例代码，可以在Unity引擎中使用：

public class BezierCurve : MonoBehaviour
{
    public Transform[] controlPoints;

    private Vector3[] positions;
    private Vector3[] normals;

    private int segments = 50;

    private Mesh mesh;

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

        positions = new Vector3[controlPoints.Length];
        normals = new Vector3[controlPoints.Length];

        for (int i = 0; i < controlPoints.Length; i++)
        {
            positions[i] = controlPoints[i].position;
        }

        CalculateNormals();

        CreateCurve();
    }

    private void CalculateNormals()
    {
        normals[0] = ((positions[1] - positions[0]) + (positions[2] - positions[0])).normalized;

        for (int i = 1; i < normals.Length - 1; i++)
        {
            normals[i] = ((positions[i + 1] - positions[i - 1]) + (positions[i + 2] - positions[i])).normalized;
        }

        normals[normals.Length - 1] = ((positions[normals.Length - 2] - positions[normals.Length - 1]) + (positions[normals.Length - 3] - positions[normals.Length - 1])).normalized;
    }

    private void CreateCurve()
    {
        Vector3[] vertices = new Vector3[segments * (controlPoints.Length - 1)];
        Vector3[] n = new Vector3[segments * (controlPoints.Length - 1)];
        int[] triangles = new int[(segments - 1) * 6 * (controlPoints.Length - 2)];

        int triIndex = 0;

        for (int i = 0; i < controlPoints.Length - 1; i++)
        {
            for (int j = 0; j < segments; j++)
            {
                float t = j / (float)segments;

                int vertexIndex = i * segments + j;
                vertices[vertexIndex