How to raycast for a specific component?

can someone help me with my code?

I am trying to get the raycast to return a hit value of a number of GameObjects with the PlanetSelection component.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class MouseManager : MonoBehaviour
6. {
7.     public GameObject selectedObject;
8.  
9.  
10.     void Update()
11.     {
12.         Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
13.         RaycastHit hitInfo;
14.    
15.             if (Physics.Raycast(ray, out hitInfo))
16.             {
17.                 /////This is where I look for the gameObjects with the PlanetSelection components.
18.                 GameObject hitObject = hitInfo.transform.GetComponent<PlanetSelection>().gameObject;
19.                
20.                     SelectObject(hitObject);
21.                
22.             }
23.             else
24.             {
25.                 ClearSelection();
26.             }
27.  
28.     }
29.  
30.     void SelectObject(GameObject obj)
31.     {
32.         if (selectedObject != null)
33.         {
34.             if (obj == selectedObject)
35.                 return;
36.             ClearSelection();
37.         }
38.         selectedObject = obj;
39.     }
40.  
41.     void ClearSelection()
42.     {
43.         selectedObject = null;
44.     }
45. }

it's telling me object reference is not set to an instance of an object....it's because I don't have any objects with the component <PlanetSelection> in the scene just yet as those are instantiated later. This is the error I get: NullReferenceException: Object reference not set to an instance of an object MouseManager.Update () (at Assets/_Scripts/MouseManager.cs:25) It's because of my Update method....How do I make it only check when there are <PlanetSelection> components in the scene?

 

I'd suggest setting up collision layers and using the raycast's layerMask first and foremost, but if you can't use layers, then you'll need to check whether GetComponent succeeds;

Code (CSharp):

1. PlanetSelection planet = hitInfo.transform.GetComponent<PlanetSelection>();
2.  
3. if (planet != null)
4. {
5.     SelectObject(planet.gameObject);
6. }

 

Thanks man!