Unity3D_ReplaceSelection.cs

/* This wizard will replace a selection with an object or prefab.
 * Scene objects will be cloned (destroying their prefab links).
 * Original coding by 'yesfish', nabbed from Unity Forums
 * 'keep parent' added by Dave A (also removed 'rotation' option, using localRotation
 * 2020/03/04 (Tobias Pott):  Updated code for use in Unity 2019.x and fixed problems with Undo/Redo insertion
 */

using System.Collections.Generic;
using UnityEditor;
using UnityEngine;

public class ReplaceSelection : ScriptableWizard
{
    private static GameObject replacement = null;
    private static bool keep = false;

    public GameObject ReplacementObject = null;
    public bool KeepOriginals = false;

    [MenuItem("GameObject/Replace Selection...")]
    private static void CreateWizard()
    {
        ScriptableWizard.DisplayWizard(
            "Replace Selection", typeof(ReplaceSelection), "Replace");
    }

    public ReplaceSelection()
    {
        ReplacementObject = replacement;
        KeepOriginals = keep;
    }

    private void OnWizardUpdate()
    {
        replacement = ReplacementObject;
        keep = KeepOriginals;
    }

    private void OnWizardCreate()
    {
        if (replacement == null)
            return;

        Transform[] transforms = Selection.GetTransforms(
            SelectionMode.TopLevel | SelectionMode.OnlyUserModifiable);

        string undoName = "Replace Selection";
        Undo.RecordObjects(transforms, undoName);
        List<GameObject> created = new List<GameObject>();

        foreach (Transform t in transforms)
        {
            GameObject g;
            PrefabAssetType pref = PrefabUtility.GetPrefabAssetType(replacement);

            if (pref != PrefabAssetType.NotAPrefab)
            {
                g = (GameObject)PrefabUtility.InstantiatePrefab(replacement);
                PrefabUtility.RecordPrefabInstancePropertyModifications(g);
            }
            else
            {
                g = (GameObject)Editor.Instantiate(replacement);
            }

            Transform gTransform = g.transform;
            gTransform.parent = t.parent;
            g.name = replacement.name;
            gTransform.localPosition = t.localPosition;
            gTransform.localScale = t.localScale;
            gTransform.localRotation = t.localRotation;

            Undo.RegisterCreatedObjectUndo(g, undoName);
            created.Add(g);

        }
        //Undo.RecordObjects(created.ToArray(), undoName);


        if (!keep)
        {
            foreach (GameObject g in Selection.gameObjects)
            {
                Undo.DestroyObjectImmediate(g);
            }
        }
    }
}