Version: 2017.2 (switch to 2017.3b)
LanguageEnglish
  • C#
  • JS

Script language

Select your preferred scripting language. All code snippets will be displayed in this language.

Physics2D.Raycast

Suggest a change

Success!

Thank you for helping us improve the quality of Unity Documentation. Although we cannot accept all submissions, we do read each suggested change from our users and will make updates where applicable.

Close

Submission failed

For some reason your suggested change could not be submitted. Please <a>try again</a> in a few minutes. And thank you for taking the time to help us improve the quality of Unity Documentation.

Close

Cancel

public static method Raycast(origin: Vector2, direction: Vector2, distance: float = Mathf.Infinity, layerMask: int = DefaultRaycastLayers, minDepth: float = -Mathf.Infinity, maxDepth: float = Mathf.Infinity): RaycastHit2D;
public static RaycastHit2D Raycast(Vector2 origin, Vector2 direction, float distance = Mathf.Infinity, int layerMask = DefaultRaycastLayers, float minDepth = -Mathf.Infinity, float maxDepth = Mathf.Infinity);

Parameters

origin The point in 2D space where the ray originates.
direction The vector representing the direction of the ray.
distance Maximum distance over which to cast the ray.
layerMask Filter to detect Colliders only on certain layers.
minDepth Only include objects with a Z coordinate (depth) greater than or equal to this value.
maxDepth Only include objects with a Z coordinate (depth) less than or equal to this value.

Returns

RaycastHit2D The cast results returned.

Description

Casts a ray against colliders in the scene.

A raycast is conceptually like a laser beam that is fired from a point in space along a particular direction. Any object making contact with the beam can be detected and reported.

This function returns a RaycastHit object with a reference to the collider that is hit by the ray (the collider property of the result will be NULL if nothing was hit). The layerMask can be used to detect objects selectively only on certain layers (this allows you to apply the detection only to enemy characters, for example).

Overloads of this method that use contactFilter can filter the results by the options available in ContactFilter2D.

Raycasts are useful for determining lines of sight, targets hit by gunfire and for many other purposes in gameplay.

Additionally, this will also detect Collider(s) at the start of the ray. In this case the ray is starting inside the Collider and doesn't intersect the Collider surface. This means that the collision normal cannot be calculated in which case the collision normal returned is set to the inverse of the ray vector being tested. This can easily be detected because such results are always at a RaycastHit2D fraction of zero.

See Also: LayerMask class, RaycastHit2D class, RaycastAll, Linecast, DefaultRaycastLayers, IgnoreRaycastLayer, raycastsHitTriggers.

// Float a rigidbody object a set distance above a surface.

var floatHeight: float; // Desired floating height. var liftForce: float; // Force to apply when lifting the rigidbody. var damping: float; // Force reduction proportional to speed (reduces bouncing).

var rb2D: Rigidbody2D;

function Start() { rb2D = GetComponent.<Rigidbody2D>(); }

function FixedUpdate() { // Cast a ray straight down. var hit: RaycastHit2D = Physics2D.Raycast(transform.position, -Vector2.up);

// If it hits something... if (hit.collider != null) { // Calculate the distance from the surface and the "error" relative // to the floating height. var distance = Mathf.Abs(hit.point.y - transform.position.y); var heightError: float = floatHeight - distance;

// The force is proportional to the height error, but we remove a part of it // according to the object's speed. var force = liftForce * heightError - rb2D.velocity.y * damping;

// Apply the force to the rigidbody. rb2D.AddForce(Vector3.up * force); } }
using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour { public float floatHeight; public float liftForce; public float damping; public Rigidbody2D rb2D; void Start() { rb2D = GetComponent<Rigidbody2D>(); } void FixedUpdate() { RaycastHit2D hit = Physics2D.Raycast(transform.position, -Vector2.up); if (hit.collider != null) { float distance = Mathf.Abs(hit.point.y - transform.position.y); float heightError = floatHeight - distance; float force = liftForce * heightError - rb2D.velocity.y * damping; rb2D.AddForce(Vector3.up * force); } } }

public static method Raycast(origin: Vector2, direction: Vector2, contactFilter: ContactFilter2D, results: RaycastHit2D[], distance: float = Mathf.Infinity): int;
public static int Raycast(Vector2 origin, Vector2 direction, ContactFilter2D contactFilter, RaycastHit2D[] results, float distance = Mathf.Infinity);

Parameters

origin The point in 2D space where the ray originates.
direction The vector representing the direction of the ray.
contactFilter The contact filter used to filter the results differently, such as by layer mask, Z depth, or normal angle.
results The array to receive results. The size of the array determines the maximum number of results that can be returned.
distance Maximum distance over which to cast the ray.

Returns

int Returns the number of results placed in the results array.

Description

Casts a ray against colliders in the Scene.

A raycast is conceptually like a laser beam that is fired from a point in space along a particular direction. Any object making contact with the beam can be detected and reported.

This function returns the number of contacts found and places those contacts in the results array. The results can also be filtered by the contactFilter.

See Also: ContactFilter2D and RaycastHit2D.

Did you find this page useful? Please give it a rating: