Physics2D.Raycast -know what you are hitting

Questions & Answers
1

Hello,
I am trying to find the object that is hit by the ray , but I cannot.

my player is doing a RayCast against the ground layer. the raycast is working as seen in the debug below. but i want to to know the name of that object so I can do CompareTag

Thanks

function FixedUpdate()
           {
             var hit: RaycastHit2D = Physics2D.Raycast(transform.position,-Vector2.up,1 << LayerMask.NameToLayer("Ground"), -2);


	      if(hit != null)

	      {
	        Debug.Log(hit.transform); //results: tree_log(Clone) (UnityEngine.Transform)
	        Debug.Log(hit.collider);  // result: tree_log(Clone) (UnityEngine.BoxCollider2D)
	        Debug.Log(hit.collider.name); //results: NullReferenceException: Object reference not set to an instance of an object
	        Debug.Log(hit.transform.name); //results: NullReferenceException: Object reference not set to an instance of an object
	      }
      }
2

Get the GameObject from the collider, from there you can extract the name:

hit.collider.gameObject.name

The 2D API will apparently return a non-null Raycast2D even when no collider is found in raycasting, so you should also test for that to determine if a collision occurred. Here’s an example you can use in testing:

#pragma strict

var target : GameObject;

var numTargets : int = 8;
var targetDistance : float = 7.0f;

var sweepSpeed = 3.0f;

var lineRender : LineRenderer;

var targetLayer : int;

var lastHit : GameObject;

function Start () {
	lineRender = GetComponent(LineRenderer);
	DuplicateTarget();	
}

function Update () {
	var radius : Vector2 = Vector2(Mathf.Cos(sweepSpeed * Time.time), Mathf.Sin(sweepSpeed * Time.time)) * targetDistance;
	
	var hit : RaycastHit2D = Physics2D.Raycast(transform.position, radius, targetDistance, 1 << targetLayer);
	
	if (null != hit && null != hit.collider) {
		lastHit = hit.collider.gameObject;
	}
	
	if (null != lineRender) {
		lineRender.SetPosition(0, transform.position);
		lineRender.SetPosition(1, transform.position + radius);
	}
}

function OnGUI() {
	var r = Rect(10f,10f,200f,100f);
	
	var label : String = "Nothing";
	if (null != lastHit) {
		label = lastHit.name;
	}
	GUI.Label(r, label);
}


function DuplicateTarget() {
	if (null != target) {
		targetLayer = target.layer;
		// Place copies of the target around the space of the sweeper.
		var origin : Vector3 = transform.position;
		var angleStep = Mathf.PI * 2.0f / numTargets;
		for (var i=0; i<numTargets; ++i) {
			var angle : float = angleStep * i;
			var r : Vector2 = Vector2( Mathf.Cos(angle), Mathf.Sin(angle)) * targetDistance;
			var newTarget : GameObject = Instantiate(target, origin + r, Quaternion.identity);
			newTarget.name = String.Format("object_{0}", i);
		}
		target.SetActive(false);
	}
}
3

hey can i know what does the line 1 << LayerMask.NameToLayer(“Ground”) does,

i think Physics2D.Raycast( vector2 , vector2 , float , int ,float ) is the function parameter list. and also antho function that is overridden
Physics2D.Raycast( vector2 , vector2 , float , int ,float , float)

where the layermask.nametolayer returns an integer .