Version: 2017.3
public int Cast (Vector2 direction, RaycastHit2D[] results, float distance= Mathf.Infinity, bool ignoreSiblingColliders= true);

Parameters

direction Vector representing the direction to cast the shape.
results Array to receive results.
distance Maximum distance over which to cast the shape.
ignoreSiblingColliders Should colliders attached to the same Rigidbody2D (known as sibling colliders) be ignored?

Returns

int The number of results returned.

Description

Casts the collider shape into the scene starting at the collider position ignoring the collider itself.

This function will take the collider shape and cast it into the scene starting at the collider position in the specified direction for an optional distance and return the results in the provided results array. The integer return value is the number of results written into the results array. 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 casts are performed frequently.

Additionally, this will also detect other Collider(s) at the collider start position if they are overlapping. In this case the cast shape will be starting inside the Collider and may not 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 direction vector being tested.

Note: Use of Collider2D.Cast() requires the use of Rigidbody2D. If no Rigidbody2D is declared Cast() does not work. However a Rigidbody2D can be static and attached to the Collider2D. This will make the Cast() work as expected. Also, if the Collider2D object has no Rigidbody2D object then it can collide with objects which have both Collider2D and Rigidbody2D objects.


public int Cast (Vector2 direction, ContactFilter2D contactFilter, RaycastHit2D[] results, float distance= Mathf.Infinity, bool ignoreSiblingColliders= true);

Parameters

direction Vector representing the direction to cast the shape.
contactFilter Filter results defined by the contact filter.
results Array to receive results.
distance Maximum distance over which to cast the shape.
ignoreSiblingColliders Should colliders attached to the same Rigidbody2D (known as sibling colliders) be ignored?

Returns

int The number of results returned.

Description

Casts the collider shape into the scene starting at the collider position ignoring the collider itself.

This function will take the collider shape and cast it into the scene starting at the collider position in the specified direction for an optional distance and return the results in the provided results array. The integer return value is the number of results written into the results array. 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 casts are performed frequently.

The contactFilter parameter, can filter the returned results by the options in ContactFilter2D.

Additionally, this will also detect other Collider(s) at the collider start position if they are overlapping. In this case the cast shape will be starting inside the Collider and may not 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 direction vector being tested.