help, how to check any collision on the direct line from 2 coord

I want to check any collision before doing the next action, but no idea how to implement.

Consider i have two object in 2D , for an example
object (4,2)
object2 (10,16)

A function to check the direct line between two coordinate (object and object2) without any (object here) collision, return true otherwise return false ? how can i check them ?

I get a stupid idea,, to create a invisible object as long as the distance by 2 coord, detect any collision with some object then destroy it. any good idea without create one more object ?

 

Use Physics2D.Raycast (https://docs.unity3d.com/ScriptReference/Physics2D.Raycast.html) cast ray from object1 in direction of object2 and limit it to magnitude of vector between object1 and object2.

1) create new Vector2 like this:

Code (CSharp):

1. Vector2 toObject2 = object2.transform.position - object1.transform.position;

2) cast ray:

Code (CSharp):

1. RaycastHit2D hit = Physics2D.Raycast(object1.transform.position, toObject2.normalized, toObject2.magnitude);
2.  
3. if (hit.collider != null) {
4.     // ... do something
5. }

 

ummm, the code not work

Code (CSharp):

1.     void attack()
2.     {
3.         RaycastHit2D hit = check();
4.  
5.         if (hit.collider == null)
6.         {
7.             shoot();
8.         }
9.     }
10.  
11.     void shoot()
12.     {
13.         Vector2 lookDir = zombie.transform.position - player.transform.position;
14.         float angle = Mathf.Atan2(lookDir.y, lookDir.x) * Mathf.Rad2Deg - 270f;
15.         firepoint.rotation = angle;
16.         bullet = Instantiate(bulletPrefab, player.transform.position, firepoint.transform.rotation);
17.         Rigidbody2D rb = bullet.GetComponent<Rigidbody2D>();
18.         rb.AddForce(lookDir * bulletforce, ForceMode2D.Impulse);
19.     }
20.  
21.     RaycastHit2D check()
22.     {
23.         Vector2 toObject2 = zombie.transform.position - player.transform.position;
24.         RaycastHit2D hit = Physics2D.Raycast(player.transform.position, toObject2.normalized, toObject2.magnitude);
25.         return hit;
26.     }

when if (hit.collider == null) // always do nothing
when if (hit.collider != null) // it will always do something even with obstacle

not work!!!!

 

You are probably hitting yourself (player) at the beginning of cast... Print hit.collider.name to see what collider was hit.

All queries in Physics2D has parameter layerMask to filter what physics layers you want to check during casts. Put your player on different layer from enemies. Then query only for enemies or enemies and obstacles (depends on what your game is about).

Also as MelvMay mentioned, you can use Linecast, it is simplier as you do not have to calculate direction and magnitude by yourself.

 

Physics2D.Linecast(player.position, zombie.position); , and the obstacle is default have collsion

still not work...........

 

Can you show how to dectec any obstacle between within two points, linear cast not working....