using UnityEngine;
#if UNITY_EDITOR
using UnityEditor;
#endif

[ExecuteInEditMode]
public class AddLODToChildren : MonoBehaviour
{
    void Awake()
    {
        #if UNITY_EDITOR
        if (!EditorApplication.isPlaying)
        {
            AddLODComponents();
        }
        #else
        AddLODComponents();
        #endif
    }

    void AddLODComponents()
    {
        Transform[] children = GetComponentsInChildren<Transform>(true);
        foreach (Transform child in children)
        {
            if (child == transform)
            {
                continue;
            }
            if (child.GetComponent<LODGroup>() == null)
            {
                Undo.AddComponent<LODGroup>(child.gameObject);
                MeshRenderer meshRenderer = child.GetComponent<MeshRenderer>();

                if (meshRenderer != null)
                {
                    LODGroup lodGroup = child.GetComponent<LODGroup>();

                    LOD[] lods = new LOD[1];
                    lods[0] = new LOD(0.01f, new Renderer[] { meshRenderer });

                    lodGroup.SetLODs(lods);
                    lodGroup.RecalculateBounds();
                }
            }
        }
    }
}