preview placement of gameobject

I have this grid where i can place a prefab on. If i click the prefab again it disapears. I got this working.
But i also want to see a/the prefab as a preview before it is clicked.

i can show the preview, but when i move to a different part of the grid, i don't know how to destroy the previewed prefab. i know i need to store the prefab and the location..then compare the locations and if they don't match destroy the stored object.

but i can't figure it out..

here is my script so far:

Code (CSharp):

1. using UnityEngine;
2.  
3. public class CubePlacer : MonoBehaviour
4. {
5.     private Grid grid;
6.  
7.     [Tooltip("The prefab to place")]
8.     public GameObject prefabPlacementObject;
9.    
10.     private void Awake()
11.     {
12.         //get grid from other script
13.         grid = FindObjectOfType<Grid>();
14.                
15.     }
16.  
17.     private void Update()
18.     {
19.         //shoot a raycast from camera to mouse
20.         RaycastHit hitInfo;
21.         Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
22.        
23.  
24.         //see if the raycast hits something
25.         if (Physics.Raycast(ray, out hitInfo))
26.         {
27.             //is the object it hits from the tag Grid
28.             if (hitInfo.collider.gameObject.tag == "Grid")
29.             {
30.                 //do we have a mouse click
31.                 if (Input.GetMouseButtonDown(0))
32.  
33.                 {
34.                     //execute function placeCubeNear
35.                     PlaceCubeNear(hitInfo.point);
36.                 }
37.                  else
38.                  {
39.                     //if mouse isn't clicked execute function previewcuenear
40.                      PreviewCubeNear(hitInfo.point);
41.                     Debug.Log("found");
42.                  }
43.             }
44.             //is the object it hits from the tag Mass
45.             if (hitInfo.collider.gameObject.tag == "Mass")
46.             {
47.                 //do we have a mouse click
48.                 if (Input.GetMouseButtonDown(0))
49.                 {
50.                     //destroy the object that is clicked
51.                     Destroy(hitInfo.collider.gameObject);
52.                 }
53.             }
54.         }
55.     }
56.     //function PlacecubeNear..function to place an object
57.     private void PlaceCubeNear(Vector3 clickPoint)
58.     {
59.         //Get the grid position from the script grid
60.         var finalPosition = grid.GetNearestPointOnGrid(clickPoint);
61.      
62.         //place the prefab on the position of the grid
63.         Instantiate(prefabPlacementObject, finalPosition, Quaternion.Euler(0, 0, 0));
64.  
65.             }
66.     //function PreviewcubeNear..function to place an object
67.     private void PreviewCubeNear(Vector3 clickPoint)
68.     {
69.         //Get the grid position from the script grid
70.         var tempPosition = grid.GetNearestPointOnGrid(clickPoint);
71.  
72.         //place the prefab on the position of the grid
73.         var placedObject = Instantiate(prefabPlacementObject, tempPosition, Quaternion.Euler(0, 0, 0));
74.  
75.        
76.         Debug.Log("script run" + tempPosition);
77.        
78.     }
79.  
80.    
81. }

 

Why don't you use one prefab preview object and just move it around to whatever tile you're hovering?

 

That is what i want..but don't know how

 

Where are you getting stuck?

 

i am placing a prefab with PreviewCubeNear...but when i move to a new grid location the element i placed at the previous location needs to be destroyed.. Or i need to make it shift position...maybe that is a better idea..
but then i need to make it into the update function i think

 

I need to do something with new vector..but i have no clu...please help


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