Cannot get 2d raycasting to work (got 3d working)

Hi there

I'm trying to make a top-down shooter, but realized that had made some messy combinations between 2d and 3d, so I decided to start over using only 2d.

I watched a tutorial on top-down shooting and ended up with a script working as intended - using 3d raycasting.

This is the script below:

Code (CSharp):

1. public class Weapons : MonoBehaviour
2. {
3.  
4.     public enum WeaponType {Semi, Burst, Auto};
5.     public WeaponType weaponType;
6.     public float rpm;
7.     public float damage;
8.     public AudioSource shotSound;
9.  
10.     public Transform hitscan_Spawn;
11.     private LineRenderer tracer;
12.  
13.     public ProjectileController projectile_Shot;
14.     public Transform projectile_FirePoint;
15.     public float projectile_Speed;
16.  
17.  
18.  
19.  
20.  
21.     private float secondsBetweenShots;
22.     private float nextPossibleShootTime;
23.  
24.     public void Start()
25.     {
26.         secondsBetweenShots = 60 / rpm;
27.         if (GetComponent<LineRenderer>())
28.         {
29.             tracer = GetComponent<LineRenderer>();
30.         }
31.     }
32.  
33.  
34.     public void Shoot()
35.     {
36.         if (CanShoot())
37.         {
38.             {
39.                 Ray ray = new Ray(hitscan_Spawn.position, hitscan_Spawn.forward);
40.                 RaycastHit hit;
41.                 float shotDistance = 20;
42.  
43.  
44.                 if (Physics.Raycast(ray, out hit, shotDistance))
45.                 {
46.                     shotDistance = hit.distance;
47.  
48.                     if (hit.collider.GetComponent<Health>())
49.                     {
50.                         hit.collider.GetComponent<Health>().TakeDamage(damage);
51.                     }
52.                 }
53.  
54.                 if (tracer)
55.                 {
56.                     StartCoroutine("RenderTracer", ray.direction * shotDistance);
57.                 }
58.             }
59.  
60.             nextPossibleShootTime = Time.time + secondsBetweenShots;
61.  
62.             shotSound.Play();    
63.         }
64.     }
65.  
66.     public void ShootContinuous()
67.     {
68.         if (weaponType == WeaponType.Auto)
69.         {
70.             Shoot();
71.         }
72.     }
73.  
74.     public bool CanShoot()
75.     {
76.         bool canShoot = true;
77.  
78.         if (Time.time < nextPossibleShootTime)
79.         {
80.             canShoot = false;
81.         }
82.  
83.         return canShoot;
84.     }
85.  
86.     IEnumerator RenderTracer(Vector3 hitPoint)
87.     {
88.         tracer.enabled = true;
89.         tracer.SetPosition(0, hitscan_Spawn.position);
90.         tracer.SetPosition(1, hitscan_Spawn.position + hitPoint);
91.         yield return null;
92.         tracer.enabled = false;
93.     }
94.  
95. }
96.  

That worked, but now that I am trying to "rebuilt" it with 2d raycasting I cannot for the life of me, figure out how to do so.
I've been trying to work with the Physics2D.Raycast and looking up the API but I'm not sure I actually understand the concept of it well enough to figure it out on my own, and I cannot find any tutorials on top-down 2d shooting.

Can anyone help or give some advice?

Thank you

 

The physics2d raycast returns either: raycasthit2d or an int , depending on which one you use.
If you only want the information for the first hit you detect (if any), using the one that returns 1 RaycastHit2D is enough, I'd say.
Just use the position of your player or weapon, the direction you want and a distance, for example.
Then, check the RaycastHit2D variable to see what you hit (if anything).
Quoted from the manual:

Though the quote says RaycastHit, I'm sure it's RaycastHit2D heh.

 

Thanks

But how do I chose the direction I want?
In 3d I can say Raycast.forward, but that is unavailable in 2d.
Should I use Raycast2D.up instead for 2d, if I want a gun to shoot and the raycast do detect trajectory?

 

Generally transform.right is the forward vector in 2D.

 

Trying to "Update" the old script to raycasting in 2D i get a "Use of unassigned variable "hit"" in the "shotDistance = hit.Distance"..
But as far as I can see I'm doing the exact same thing in the 3d script, but there it's not "unassigned"

Code (CSharp):

1.  
2.     public void Shoot()
3.     {
4.         if (CanShoot())
5.         {
6.             {
7.                 Ray2D ray2D = new Ray2D(firePos.position, firePos.right);
8.                 RaycastHit2D hit;
9.                 float shotDistance = 20;
10.  
11.  
12.                 if (Physics2D.Raycast(firePos.position, transform.right, shotDistance))
13.                 {
14.                     shotDistance = hit.distance;
15.                     if (hit.collider.GetComponent<Health>())
16.                     {
17.                         hit.collider.GetComponent<Health>().TakeDamage(damage);
18.                     }
19.                 }
20.  

What am I misunderstanding here?

 

It doesn't return a bool like the 3d version. So, you want to modify your code a little. You'll always get a hit, as I tried to mention before, so you want to check the collider of the hit (or some other property I suppose should work, too).

Code (csharp):

1. hit = Physics2D.Raycast(firePos.position, transform.right, shotDistance));
2. if(hit.collider != NULL) {
3.  // rest of your code..
4.   }
5.  

 

I still can't get it to work.
I'm going crazy over this

You can see my current code below:

Code (CSharp):

1.     public void Shoot()
2.     {
3.         if (CanShoot())
4.         {
5.             {
6.                 Ray2D ray2D = new Ray2D(firePos.position, firePos.up);
7.                 RaycastHit2D hit;
8.                 float shotDistance = 20;
9.  
10.                 hit = Physics2D.Raycast(firePos.position, firePos.up, shotDistance);
11.                 if (hit.collider != null)
12.                 {
13.                     shotDistance = hit.distance;
14.                     if (hit.collider.GetComponent<Health>())
15.                     {
16.                         hit.collider.GetComponent<Health>().TakeDamage(damage);
17.                     }
18.                 }
19.  
20.                 Debug.DrawRay(firePos.position, firePos.up, Color.red);
21.  
22.                 if (tracer)
23.                 {
24.                     StartCoroutine("RenderTracer", ray2D.direction * shotDistance);
25.                 }
26.             }
27.  
28.             nextPossibleShootTime = Time.time + secondsBetweenShots;
29.  
30.             shotSound.Play();
31.         }
32.     }
33.  
34.     public void ShootContinuous()
35.     {
36.         if (weaponType == WeaponType.Auto)
37.         {
38.             Shoot();
39.         }
40.     }
41.  
42.     public bool CanShoot()
43.     {
44.         bool canShoot = true;
45.  
46.         if (Time.time < nextPossibleShootTime)
47.         {
48.             canShoot = false;
49.         }
50.  
51.         return canShoot;
52.     }
53.  
54.     IEnumerator RenderTracer(Vector2 hitPoint)
55.     {
56.         tracer.enabled = true;
57.         tracer.SetPosition(0, firePos.position);
58.         tracer.SetPosition(1, new Vector3(firePos.position.x + hitPoint.x, firePos.position.y + hitPoint.y));
59.         yield return null;
60.         tracer.enabled = false;
61.     }

My Debug.DrawRay seem to work normally, but I can't get that damn linerenderer to work.
It seems to me that it's the "SetPosition(1.... .....) that's wrong, although I get no Errors, but I cannot figure out what to do.