Unityでカメラのインスペクタに注視点で角度設定するボタンをつけるエディタ拡張のスクリプト

LookAtCameraEditor.cs

using UnityEngine;
using UnityEditor;

[CustomEditor(typeof(Camera))]
public class LookAtCameraEditor : Editor
{
	Vector3 value;
	public override void OnInspectorGUI()
	{
		DrawDefaultInspector();
		EditorGUILayout.BeginHorizontal();
		value = EditorGUILayout.Vector3Field("target", value);
		if (GUILayout.Button("Look", GUILayout.MaxWidth(60)))
		{
			Camera c = target as Camera;
			Undo.RecordObject(c, "Camera LookAt");
			c.transform.rotation = Quaternion.LookRotation(value - c.transform.position);
			EditorUtility.SetDirty(target);
		}
		EditorGUILayout.EndHorizontal();
	}
}