Unity Script Reference – Physics.Raycast

static function Raycast (origin : Vector3, direction : Vector3, distance : float = Mathf.Infinity, layerMask : int = kDefaultRaycastLayers) : bool

Parameters

Name	Description
origin	The starting point of the ray in world coordinates.
direction	The direction of the ray.
distance	The length of the ray
layerMask	A Layer mask that is used to selectively ignore colliders when casting a ray.

Returns

bool - True when the ray intersects any collider, otherwise false.

Description

Casts a ray against all colliders in the scene.

JavaScripts

function Update () {
var fwd = transform.TransformDirection (Vector3.forward);
if (Physics.Raycast (transform.position, fwd, 10)) {
print ("There is something in front of the object!");
}
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
void Update() {
Vector3 fwd = transform.TransformDirection(Vector3.forward);
if (Physics.Raycast(transform.position, fwd, 10))
print("There is something in front of the object!");

}
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

def Update():
fwd as Vector3 = transform.TransformDirection(Vector3.forward)
if Physics.Raycast(transform.position, fwd, 10):
print('There is something in front of the object!')

Note: This function will return false if you cast a ray from inside a sphere to the outside; this in an intended behaviour.

static function Raycast (origin : Vector3, direction : Vector3, out hitInfo : RaycastHit, distance : float = Mathf.Infinity, layerMask : int = kDefaultRaycastLayers) : bool

Parameters

Name	Description
origin	The starting point of the ray in world coordinates.
direction	The direction of the ray.
distance	The length of the ray
hitInfo	If true is returned, hitInfo will contain more information about where the collider was hit (See Also: RaycastHit).
layerMask	A Layer mask that is used to selectively ignore colliders when casting a ray.

Returns

bool - True when the ray intersects any collider, otherwise false.

Description

Casts a ray against all colliders in the scene and returns detailed information on what was hit.

JavaScripts

function Update () {
var hit : RaycastHit;
if (Physics.Raycast (transform.position, -Vector3.up, hit)) {
var distanceToGround = hit.distance;
}
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
void Update() {
RaycastHit hit;
if (Physics.Raycast(transform.position, -Vector3.up, out hit))
float distanceToGround = hit.distance;

}
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

def Update():
hit as RaycastHit
if Physics.Raycast(transform.position, -Vector3.up, hit):
distanceToGround as single = hit.distance

another example:

JavaScripts

// Raycast up to 100 meters forward

function Update () {
var hit : RaycastHit;
if (Physics.Raycast (transform.position, -Vector3.up, hit, 100.0)) {
var distanceToGround = hit.distance;
}
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
void Update() {
RaycastHit hit;
if (Physics.Raycast(transform.position, -Vector3.up, out hit, 100.0F))
float distanceToGround = hit.distance;

}
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

def Update():
hit as RaycastHit
if Physics.Raycast(transform.position, -Vector3.up, hit, 100.0F):
distanceToGround as single = hit.distance

static function Raycast (ray : Ray, distance : float = Mathf.Infinity, layerMask : int = kDefaultRaycastLayers) : bool

Parameters

Name	Description
ray	The starting point and direction of the ray.
distance	The length of the ray
layerMask	A Layer mask that is used to selectively ignore colliders when casting a ray.

Returns

bool - True when the ray intersects any collider, otherwise false.

Description

Same as above using ray.origin and ray.direction instead of origin and direction.

JavaScripts

var ray = Camera.main.ScreenPointToRay (Input.mousePosition);
if (Physics.Raycast (ray, 100)) {
print ("Hit something");
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
public Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
void Awake() {
if (Physics.Raycast(ray, 100))
print("Hit something");

}
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

public ray as Ray = Camera.main.ScreenPointToRay(Input.mousePosition)

def Awake():
if Physics.Raycast(ray, 100):
print('Hit something')

static function Raycast (ray : Ray, out hitInfo : RaycastHit, distance : float = Mathf.Infinity, layerMask : int = kDefaultRaycastLayers) : bool

Parameters

Name	Description
ray	The starting point and direction of the ray.
distance	The length of the ray
hitInfo	If true is returned, hitInfo will contain more information about where the collider was hit (See Also: RaycastHit).
layerMask	A Layer mask that is used to selectively ignore colliders when casting a ray.

Returns

bool - True when the ray intersects any collider, otherwise false.

Description

Same as above using ray.origin and ray.direction instead of origin and direction.

JavaScripts

var ray = Camera.main.ScreenPointToRay (Input.mousePosition);
var hit : RaycastHit;
if (Physics.Raycast (ray, hit, 100)) {
Debug.DrawLine (ray.origin, hit.point);
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
public Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
public RaycastHit hit;
void Awake() {
if (Physics.Raycast(ray, out hit, 100))
Debug.DrawLine(ray.origin, hit.point);

}
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

public ray as Ray = Camera.main.ScreenPointToRay(Input.mousePosition)

public hit as RaycastHit

def Awake():
if Physics.Raycast(ray, hit, 100):
Debug.DrawLine(ray.origin, hit.point)