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Unity Engine


Raycast

Casts a ray into the Scene that starts at the Collider position and ignores the Collider itself.
Read time 5 minutesLast updated 4 days ago

Definition

  • Type: Method
  • Namespace: UnityEngine
  • Assembly: UnityEngine.Physics2DModule

Raycast(Vector2, RaycastHit2D[], float, int, float, float)

Casts a ray into the Scene that starts at the Collider position and ignores the Collider itself.
public int Raycast(Vector2 direction, RaycastHit2D[] results, float distance, int layerMask, float minDepth, float maxDepth)

Parameters

direction

Vector representing the direction of the ray.

Array to receive results.

distance

Maximum distance over which to cast the ray.

layerMask

Filter to check objects only on specific layers.

minDepth

Only include objects with a Z coordinate (depth) greater than this value.

maxDepth

Only include objects with a Z coordinate (depth) less than this value.

Returns

Type

Description

intThe number of results returned.

Remarks

The integer return value is the number of objects that intersect the ray (possibly zero) but the results array will not be resized if it doesn't contain enough elements to report all the results. The significance of this is that no memory is allocated for the results and so garbage collection performance is improved when raycasts are performed frequently.
Overloads of this function that use
contactFilter
filters the results by the options available in ContactFilter2D.
Additionally, this will also detect other 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.
NOTE: All results are sorted into ascending distance order i.e. the first result is the closest.

Raycast(Vector2, ContactFilter2D, RaycastHit2D[], float)

Casts a ray into the Scene that starts at the Collider position and ignores the Collider itself.
public int Raycast(Vector2 direction, ContactFilter2D contactFilter, RaycastHit2D[] results, float distance)

Parameters

direction

Vector representing the direction of the ray.

contactFilter

Filter results defined by the contact filter.

Array to receive results.

distance

Maximum distance over which to cast the ray.

Returns

Type

Description

intThe number of results returned.

Remarks

The integer return value is the number of objects that intersect the ray (possibly zero) but the results array will not be resized if it doesn't contain enough elements to report all the results. The significance of this is that no memory is allocated for the results and so garbage collection performance is improved when raycasts are performed frequently.
Overloads of this function that use
contactFilter
filters the results by the options available in ContactFilter2D.
Additionally, this will also detect other 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.
NOTE: All results are sorted into ascending distance order i.e. the first result is the closest.

Raycast(Vector2, ContactFilter2D, List<RaycastHit2D>, float)

Casts a ray into the Scene that starts at the Collider position and ignores the Collider itself.
public int Raycast(Vector2 direction, ContactFilter2D contactFilter, List<RaycastHit2D> results, float distance = Infinity)

Parameters

direction

Vector representing the direction of the ray.

contactFilter

Filter results defined by the contact filter.

List to receive results.

distance

Maximum distance over which to cast the ray.

Returns

Type

Description

intThe number of results returned.

Remarks

The integer return value is the number of Colliders that intersect the ray (possibly zero). The results list will be resized if it doesn't contain enough elements to report all the results. This prevents memory from being allocated for results when the
results
list does not need to be resized, and improves garbage collection performance when the query is performed frequently.
Additionally, this will also detect other 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.
NOTE: All results are sorted into ascending distance order i.e. the first result is the closest.
Additional Resources: RaycastHit2D

Raycast(Vector2, ContactFilter2D, float, Allocator)

Casts a ray into the Scene that starts at the Collider position and ignores the Collider itself.
public NativeArray<RaycastHit2D> Raycast(Vector2 direction, ContactFilter2D contactFilter, float distance = Infinity, Allocator allocator = Allocator.Temp)

Parameters

direction

Vector representing the direction of the ray.

contactFilter

Filter results defined by the contact filter.

distance

Maximum distance over which to cast the ray.

allocator

The memory allocator to use for the results. This can only be Allocator.Temp, Allocator.TempJob or Allocator.Persistent.

Returns

Type

Description

NativeArray<RaycastHit2D>The NativeArray that contains the results. This must be disposed of unless it contains no results.

Remarks

Additionally, this will also detect other 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.
NOTE: All results are sorted into ascending distance order i.e. the first result is the closest.
Additional Resources: RaycastHit2D