unity 通过代码生成 胶囊体mesh

可以使用Unity自带的Mesh类来生成胶囊体的Mesh。以下是示例代码：

using UnityEngine;

public class CapsuleGenerator : MonoBehaviour
{
    public float radius = 0.5f;
    public float height = 2.0f;
    public int segments = 16;

    void Start()
    {
        MeshFilter meshFilter = GetComponent<MeshFilter>();
        if (meshFilter == null)
        {
            meshFilter = gameObject.AddComponent<MeshFilter>();
        }

        Mesh mesh = new Mesh();
        meshFilter.mesh = mesh;

        Vector3[] vertices = new Vector3[(segments + 1) * 2 + segments * 2];
        int[] triangles = new int[segments * 6 * 2 + segments * 3 * 2];

        float angleStep = Mathf.PI * 2.0f / segments;

        // Generate top and bottom caps
        for (int i = 0; i <= segments; i++)
        {
            float angle = angleStep * i;
            float x = Mathf.Cos(angle) * radius;
            float z = Mathf.Sin(angle) * radius;

            vertices[i] = new Vector3(x, height * 0.5f, z);
            vertices[i + segments + 1] = new Vector3(x, -height * 0.5f, z);
        }

        // Generate cylinder body
        int vertexIndex = (segments + 1) * 2;
        for (int i = 0; i < segments; i++)
        {
            float angle = angleStep * i;
            float x = Mathf.Cos(angle) * radius;
            float z = Mathf.Sin(angle) * radius;

            vertices[vertexIndex] = new Vector3(x, height * 0.5f, z);
            vertices[vertexIndex + 1] = new Vector3(x, -height * 0.5f, z);

            vertexIndex += 2;
        }

        // Generate top cap triangles
        int triangleIndex = 0;
        for (int i = 0; i < segments; i++)
        {
            triangles[triangleIndex++] = i;
            triangles[triangleIndex++] = i + 1;
            triangles[triangleIndex++] = i + segments + 1;
        }

        // Generate bottom cap triangles
        for (int i = 0; i < segments; i++)
        {
            triangles[triangleIndex++] = i + segments + 2;
            triangles[triangleIndex++] = i + 1 + segments + 2;
            triangles[triangleIndex++] = i + segments + 1 + segments + 2;
        }

        // Generate cylinder body triangles
        for (int i = 0; i < segments; i++)
        {
            int vi = (segments + 1) * 2 + i * 2;
            triangles[triangleIndex++] = vi;
            triangles[triangleIndex++] = vi + 1;
            triangles[triangleIndex++] = vi + 2;

            triangles[triangleIndex++] = vi + 2;
            triangles[triangleIndex++] = vi + 1;
            triangles[triangleIndex++] = vi + 3;
        }

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

这段代码会在场景中创建一个空物体，并在其上添加一个MeshFilter组件和一个CapsuleGenerator脚本。在CapsuleGenerator脚本中，我们使用Mesh类来生成胶囊体的Mesh，并将其赋值给MeshFilter组件的mesh属性。在Start()方法中，我们首先生成顶部和底部的圆盖，并将它们放在顶部和底部。然后，我们生成圆柱体的侧面，并将它们放在中间。最后，我们生成三角形索引数组，并将其赋值给Mesh类的triangles属性。