Resolved Grabbing system

I want a grabbing system that will put the object in front of the camera, and keep it there until the user presses the grab button again. I have the raycast set up and everything, the only thing i need is an equation that puts it in front of the camera. i have tried many things, but nothing seems to work. can anayone help please?

 

Untested:

Vector3 worldPositionAhead = Camera.main.transform.forward * distanceFromCamera;

Edit: plus camera position..

Vector3 worldPositionAhead = Camera.main.transform.position + (Camera.main.transform.forward * distanceFromCamera);

 

i tried it, but i don't know how to implement it into my current grab code. here is that code:

Code (CSharp):

1. using UnityEngine;
2.  
3. public class SelectionManager : MonoBehaviour
4. {
5.     [SerializeField] private string selectableTag = "Selectable";
6.     [SerializeField] private Material highlightMaterial;
7.     [SerializeField] private Material defaultMaterial;
8.  
9.     private Transform _selection;
10.  
11.     public Transform camera;
12.    
13.     private void Update()
14.     {
15.         if (_selection != null)
16.         {
17.             var selectionRenderer = _selection.GetComponent<Renderer>();
18.             selectionRenderer.material = defaultMaterial;
19.             _selection = null;
20.         }
21.        
22.         var ray = Camera.main.ScreenPointToRay(Input.mousePosition);
23.         RaycastHit hit;
24.         if (Physics.Raycast(ray, out hit))
25.         {
26.             var selection = hit.transform;
27.             if (selection.CompareTag(selectableTag))
28.             {
29.                 var selectionRenderer = selection.GetComponent<Renderer>();
30.                 if (selectionRenderer != null)
31.                 {
32.                     selectionRenderer.material = highlightMaterial;
33.                 }
34.  
35.                 _selection = selection;
36.  
37.                 if (Input.GetKeyDown(KeyCode.E))
38.                 {
39.                     UnityEngine.Debug.Log("Block Grabbed");
40.  
41.                     //equation here
42.                 }
43.             }
44.         }
45.     }
46. }

 

you're setting selection to null on the frame after it's set. you'll want to keep a reference around, or maybe add a

public Transform grabbed

; then where you have "equation here" you would put

grabbed = selection;

and somewhere else in Update (maybe at the bottom) add something like..

Code (CSharp):

1. if (grabbed != null) grabbed.position = Camera.main.transform.position + (Camera.main.transform.forward * 10.0f);

 

would 'grabbed' be the object your grabbing?

 

and actually, after a bit of experimenting, i got it to teleport to the right spot, except the only problem is that it only teleports once and then stops. any fix?

current code:

Code (CSharp):

1. using UnityEngine;
2.  
3. public class SelectionManager : MonoBehaviour
4. {
5.     [SerializeField] private string selectableTag = "Selectable";
6.     [SerializeField] private Material highlightMaterial;
7.     [SerializeField] private Material defaultMaterial;
8.  
9.     private Transform _selection;
10.  
11.     public Transform camera;
12.     public bool grabbing;
13.    
14.     private void Update()
15.     {
16.         if (_selection != null)
17.         {
18.             var selectionRenderer = _selection.GetComponent<Renderer>();
19.             selectionRenderer.material = defaultMaterial;
20.             _selection = null;
21.         }
22.        
23.         var ray = Camera.main.ScreenPointToRay(Input.mousePosition);
24.         RaycastHit hit;
25.         if (Physics.Raycast(ray, out hit))
26.         {
27.             var selection = hit.transform;
28.             if (selection.CompareTag(selectableTag))
29.             {
30.                 var selectionRenderer = selection.GetComponent<Renderer>();
31.                 if (selectionRenderer != null)
32.                 {
33.                     selectionRenderer.material = highlightMaterial;
34.                 }
35.  
36.                 _selection = selection;
37.  
38.                 if (Input.GetKeyDown(KeyCode.E))
39.                 {
40.                     UnityEngine.Debug.Log("Block Grabbed");
41.                     if (selection != null) selection.position = camera.position + (camera.forward * 3.0f);
42.                 }
43.             }
44.         }
45.        
46.     }
47. }

 

The issue is this:

Code (CSharp):

1. private void Update()
2.     {
3.         if (_selection != null)
4.         {
5.             //[...]
6.             _selection = null;

The very next frame you don't have a reference anymore, because you set that to null. If you want to keep holding it in front of you, there needs to be a reference - that's why I said you should add "grabbed" and use that. Try this..

Code (CSharp):

1. using UnityEngine;
2. public class SelectionManager : MonoBehaviour
3. {
4.     [SerializeField] private string selectableTag = "Selectable";
5.     [SerializeField] private Material highlightMaterial;
6.     [SerializeField] private Material defaultMaterial;
7.     private Transform _selection;
8.     private Transform _grabbed;
9.     public Transform camera;
10.     public bool grabbing;
11.  
12.     private void Update()
13.     {
14.         if (_selection != null)
15.         {
16.             var selectionRenderer = _selection.GetComponent<Renderer>();
17.             selectionRenderer.material = defaultMaterial;
18.             _selection = null;
19.         }
20.  
21.       if (_grabbed != null)
22.       {
23.         if (Input.GetKeyDown(KeyCode.E))
24.         {
25.           Debug.Log("No longer grabbing");
26.           _grabbed = null;
27.         } else {
28.           _grabbed.position = camera.position + (camera.forward * 3.0f);
29.         }
30.         return;
31.       }
32.      
33.         var ray = Camera.main.ScreenPointToRay(Input.mousePosition);
34.         RaycastHit hit;
35.         if (Physics.Raycast(ray, out hit))
36.         {
37.             var selection = hit.transform;
38.             if (selection.CompareTag(selectableTag))
39.             {
40.                 var selectionRenderer = selection.GetComponent<Renderer>();
41.                 if (selectionRenderer != null)
42.                 {
43.                     selectionRenderer.material = highlightMaterial;
44.                 }
45.                 _selection = selection;
46.                 if (Input.GetKeyDown(KeyCode.E))
47.                 {
48.                   _grabbed = _selection;
49.                     UnityEngine.Debug.Log("Block Grabbed");
50.                 }
51.             }
52.         }
53.      
54.     }
55. }

 

the code worked great! thank you so much.