Why all the cloned objects are not childs under gameobject Sphere?

Question

It did work before but i can't figure out what is wrong now. In the Hierarchy i have a GameObject i renamed it to Sphere. This Sphere is tagged as Sphere.

But when running the game all the cloned objects are in the hierarchy and not as childs inside Sphere. The Sphere it self is gone delete when running the game.

This is a screenshot of the Sphere gameobject before running the game: The script Sphere Builder is attached to Sphere:

This screenshot is when running the game: All the clones should be under Sphere gameobject:

This is the script:

using System;
using UnityEngine;
using Random = UnityEngine.Random;
using System.Collections;
using System.Collections.Generic;

public class SphereBuilder : MonoBehaviour
{
    public GameObject SpaceShip;

    // for tracking properties change
    private Vector3 _extents;
    private int _sphereCount;
    private float _sphereSize;

    /// <summary>
    ///     How far to place spheres randomly.
    /// </summary>
    public Vector3 Extents;

    /// <summary>
    ///     How many spheres wanted.
    /// </summary>
    public int SphereCount;
    public float SphereSize;

    private void OnValidate()
    {
        // prevent wrong values to be entered
        Extents = new Vector3(Mathf.Max(0.0f, Extents.x), Mathf.Max(0.0f, Extents.y), Mathf.Max(0.0f, Extents.z));
        SphereCount = Mathf.Max(0, SphereCount);
        SphereSize = Mathf.Max(0.0f, SphereSize);
    }

    private void Reset()
    {
        Extents = new Vector3(250.0f, 20.0f, 250.0f);
        SphereCount = 100;
        SphereSize = 20.0f;
    }

    private void Update()
    {
        UpdateSpheres();
    }

    private void UpdateSpheres()
    {
        if (Extents == _extents && SphereCount == _sphereCount && Mathf.Approximately(SphereSize, _sphereSize))
            return;

        // cleanup
        var spheres = GameObject.FindGameObjectsWithTag("Sphere");
        foreach (var t in spheres)
        {
            if (Application.isEditor)
            {
                DestroyImmediate(t);
            }
            else
            {
                Destroy(t);
            }
        }

        var withTag = GameObject.FindWithTag("Terrain");
        if (withTag == null)
            throw new InvalidOperationException("Terrain not found");

        for (var i = 0; i < SphereCount; i++)
        {
            var o = Instantiate(SpaceShip);
            o.tag = "Sphere";
            o.transform.localScale = new Vector3(SphereSize, SphereSize, SphereSize);

            // get random position
            var x = Random.Range(-Extents.x, Extents.x);
            var y = Extents.y; // sphere altitude relative to terrain below
            var z = Random.Range(-Extents.z, Extents.z);

            // now send a ray down terrain to adjust Y according terrain below
            var height = 10000.0f; // should be higher than highest terrain altitude
            var origin = new Vector3(x, height, z);
            var ray = new Ray(origin, Vector3.down);
            RaycastHit hit;
            var maxDistance = 20000.0f;
            var nameToLayer = LayerMask.NameToLayer("Terrain");
            var layerMask = 1 << nameToLayer;
            if (Physics.Raycast(ray, out hit, maxDistance, layerMask))
            {
                var distance = hit.distance;
                y = height - distance + y; // adjust
            }
            else
            {
                Debug.LogWarning("Terrain not hit, using default height !");
            }

            // place !
            o.transform.position = new Vector3(x, y, z);
        }

        _extents = Extents;
        _sphereCount = SphereCount;
        _sphereSize = SphereSize;
    }
}

Answer 1

实例化对象后，设置转换父级。

o.transform.SetParent(gameObject.transform);