Unity/Editor/inspector値更新

SampleScene.cs

using UnityEngine;

public class SampleScene : MonoBehaviour
{
    [SerializeField] GameObject testObject;
    [SerializeField] int num;
    // Start is called before the first frame update
    void Start()
    {
        
    }

    // Update is called once per frame
    void Update()
    {
        
    }
}

SampleSceneInspectorEditor.cs

using UnityEngine;
using UnityEditor;

[CustomEditor(typeof(SampleScene))]
public class SampleSceneInspectorEditor : Editor
{
    public override void OnInspectorGUI()
    {
        serializedObject.Update();

        var testObject = serializedObject.FindProperty("testObject");
        var num = serializedObject.FindProperty("num");

        num.intValue = 3;
        testObject.objectReferenceValue = GameObject.Find("TestObject");
        
        EditorGUILayout.PropertyField(testObject);
        EditorGUILayout.PropertyField(num);

        serializedObject.ApplyModifiedProperties();
    }
}

参考：https://www.hanachiru-blog.com/entry/2020/10/19/120000#SerializedObject%E3%82%92%E4%BD%BF%E3%81%A3%E3%81%9F%E3%82%84%E3%82%8A%E6%96%B9