a

Assets/Objects/way_normal.asset

@@ -14,5 +14,5 @@ MonoBehaviour:
   m_EditorClassIdentifier: 
   nameString: Way
   prefab: {fileID: 3420327930372171566, guid: 1b0d9211d89253549b71b121b268c59b, type: 3}
-  width: 1
+  width: 2
   height: 1

Assets/Objects/way_normal.prefab

@@ -10,6 +10,7 @@ GameObject:
   m_Component:
   - component: {fileID: 3420327930372171566}
   - component: {fileID: 3420327930372171567}
+  - component: {fileID: 7845977379617268391}
   m_Layer: 0
   m_Name: way_normal
   m_TagString: Untagged
@@ -84,3 +85,15 @@ SpriteRenderer:
   m_WasSpriteAssigned: 1
   m_MaskInteraction: 0
   m_SpriteSortPoint: 0
+--- !u!114 &7845977379617268391
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 3420327930372171564}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: 56fadc4f2b895ad46bda623c68601c7e, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: 

Assets/Scenes/GridScene.unity

@@ -268,7 +268,8 @@ MonoBehaviour:
   m_Script: {fileID: 11500000, guid: a9e8b2a885476754e9652c90137f91bc, type: 3}
   m_Name: 
   m_EditorClassIdentifier: 
-  placedObjectTypeSO: {fileID: 11400000, guid: b08e32832db84ca489b3dd705df7eff7, type: 2}
+  placedObjectTypeSOList:
+  - {fileID: 11400000, guid: b08e32832db84ca489b3dd705df7eff7, type: 2}
 --- !u!4 &1522634446
 Transform:
   m_ObjectHideFlags: 0

Assets/Scripts/Grid/GridBuildingSystem.cs

@@ -5,7 +5,8 @@ using UnityEngine;
 // Written with https://www.youtube.com/watch?v=dulosHPl82A
 public class GridBuildingSystem : MonoBehaviour
 {
-    [SerializeField] PlacedObjectTypeSO placedObjectTypeSO;
+    [SerializeField] List<PlacedObjectTypeSO> placedObjectTypeSOList = new List<PlacedObjectTypeSO>(); // https://youtu.be/dulosHPl82A?t=1192
+    PlacedObjectTypeSO placedObjectTypeSO;
 
     Grid<GridObject> grid;
     void Awake()
@@ -15,25 +16,26 @@ public class GridBuildingSystem : MonoBehaviour
         float cellSize = 2f;
 
         grid = new Grid<GridObject>(gridWidth, gridHeight, cellSize, Vector3.zero, (Grid<GridObject> g, int x, int y) => new GridObject(g, x, y));
+        placedObjectTypeSO = placedObjectTypeSOList[0];
     }
     public class GridObject
     {
         int x, y;
         Grid<GridObject> grid;
-        Transform transform;
+        PlacedObject placedObject;
         public GridObject(Grid<GridObject> _grid, int _x, int _y)
         {
             grid = _grid;
             x = _x;
             y = _y;
         }
-        public void SetTransform(Transform _transform) => transform = _transform;
-        public Transform GetTransform() => transform;
-        public void ClearTransform() => transform = null;
+        public void SetPlacedObject(PlacedObject _placedObject) => placedObject = _placedObject;
+        public PlacedObject GetPlacedObject() => placedObject;
+        public void ClearPlacedObject() => placedObject = null;
 
         public bool CanBuild()
         {
-            return transform == null;
+            return placedObject == null;
         }
     }
     void Update()
@@ -58,11 +60,12 @@ public class GridBuildingSystem : MonoBehaviour
 
             if (canBuild)
             {
-                Transform builtTransform = Instantiate(placedObjectTypeSO.prefab, grid.GetWorldPosition(x, y), Quaternion.identity);
+                PlacedObject placedObject = PlacedObject.Create(grid.GetWorldPosition(x, y), new Vector2Int(x, y), PlacedObjectTypeSO.Dir.Down, placedObjectTypeSO);
+                
                 
                 foreach(Vector2Int gridPosition in gridPositionList)
                 {
-                    grid.GetGridObject(gridPosition.x, gridPosition.y).SetTransform(builtTransform);
+                    grid.GetGridObject(gridPosition.x, gridPosition.y).SetPlacedObject(placedObject);
                 }
                 
             }
@@ -70,6 +73,22 @@ public class GridBuildingSystem : MonoBehaviour
             {
                 Debug.Log("Cannot build here!" + " " + mousePosition);
             }
+        }else if (Input.GetMouseButtonDown(1))
+        {
+            GridObject gridObject = grid.GetGridObject(Camera.main.ScreenToWorldPoint(Input.mousePosition));
+            PlacedObject placedObject = gridObject.GetPlacedObject();
+            if (placedObject != null)
+            {
+                placedObject.DestroySelf();
+
+                List<Vector2Int> gridPositionList = placedObject.GetGridPositionList();
+
+                foreach (Vector2Int gridPosition in gridPositionList)
+                {
+                    grid.GetGridObject(gridPosition.x, gridPosition.y).ClearPlacedObject();
+                }
+            }
+
         }
     }
 }

Assets/Scripts/PlacedObject.cs

@@ -0,0 +1,31 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class PlacedObject : MonoBehaviour
+{
+    public static PlacedObject Create(Vector3 worldPosition, Vector2Int origin, PlacedObjectTypeSO.Dir dir, PlacedObjectTypeSO placedObjectTypeSO)
+    {
+        Transform placeObjectTransform = Instantiate(placedObjectTypeSO.prefab, worldPosition, Quaternion.identity);
+
+        PlacedObject placedObject = placeObjectTransform.GetComponent<PlacedObject>();
+        placedObject.placedObjectTypeSO = placedObjectTypeSO;
+        placedObject.origin = origin;
+        placedObject.dir = dir;
+        return placedObject;
+    }
+
+    PlacedObjectTypeSO placedObjectTypeSO;
+    Vector2Int origin;
+    PlacedObjectTypeSO.Dir dir;
+
+    public List<Vector2Int> GetGridPositionList()
+    {
+        return placedObjectTypeSO.GetGridPositionList(origin, PlacedObjectTypeSO.Dir.Down);
+    }
+
+    public void DestroySelf()
+    {
+        Destroy(gameObject);
+    }
+}

Assets/Scripts/PlacedObject.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 56fadc4f2b895ad46bda623c68601c7e
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: