Physics.Raycast

Parameters

Returns

bool True if the ray intersects with a Collider, otherwise false.

Description

Casts a ray, from point origin, in direction direction, of length maxDistance, against all colliders in the scene.

You may optionally provide a LayerMask, to filter out any Colliders you aren't interested in generating collisions with.

Specifying queryTriggerInteraction allows you to control whether or not Trigger colliders generate a hit, or whether to use the global Physics.queriesHitTriggers setting.

This example creates a simple Raycast, projecting forwards from the position of the object's current position, extending for 10 units.

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

using UnityEngine;

public class ExampleClass : MonoBehaviour
{
    void FixedUpdate()
    {
        Vector3 fwd = transform.TransformDirection(Vector3.forward);

        if (Physics.Raycast(transform.position, fwd, 10))
            print("There is something in front of the object!");
    }
}

Notes: Raycasts will not detect Colliders for which the Raycast origin is inside the Collider.

Parameters

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.

This example reports the distance between the current object and the reported Collider:

#pragma strict
public class RaycastExample extends MonoBehaviour {
	function FixedUpdate() {
		var hit: RaycastHit;
		if (Physics.Raycast(transform.position, -Vector3.up, hit))
			print("Found an object - distance: " + hit.distance);
	}
}

using UnityEngine;

public class RaycastExample : MonoBehaviour
{
    void FixedUpdate()
    {
        RaycastHit hit;

        if (Physics.Raycast(transform.position, -Vector3.up, out hit))
            print("Found an object - distance: " + hit.distance);
    }
}

This example re-introduces the maxDistance parameter to limit how far ahead to cast the Ray:

#pragma strict
public class RaycastExample extends MonoBehaviour {
	function FixedUpdate() {
		var hit: RaycastHit;
		if (Physics.Raycast(transform.position, -Vector3.up, hit, 100.0f))
			print("Found an object - distance: " + hit.distance);
	}
}

using UnityEngine;

public class RaycastExample : MonoBehaviour
{
    void FixedUpdate()
    {
        RaycastHit hit;

        if (Physics.Raycast(transform.position, -Vector3.up, out hit, 100.0f))
            print("Found an object - distance: " + hit.distance);
    }
}

Parameters

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.

#pragma strict
function Update() {
	var ray: Ray = Camera.main.ScreenPointToRay(Input.mousePosition);
	if (Physics.Raycast(ray, 100))
		print("Hit something!");
}

using UnityEngine;

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

Parameters

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.

This example draws a line along the length of the Ray whenever a collision is detected:

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

using UnityEngine;

public class ExampleClass : MonoBehaviour
{
    void Update()
    {
        Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
        RaycastHit hit;

        if (Physics.Raycast(ray, out hit, 100))
            Debug.DrawLine(ray.origin, hit.point);
    }
}