| ray | 定义要测试的原点和方向的 3D 射线。 |
| distance | 光线的最大投射距离。 |
| layerMask | 过滤器，用于仅在特定层上检测碰撞体。 |
RaycastHit2D 返回的投射数量。
Cast a 3D ray against the colliders in the PhysicsScene2D, returning the first intersection only.
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. Raycasts are useful for determining lines of sight, targets hit by gunfire and for many other purposes in gameplay.
Unlike Raycast which performs a 2D intersection test, this function performs a 3D intersection test on 2D colliders. It does this by projecting the 3D ray into 2D space then performs the 2D intersection test, ordering the results by the Z direction of the original 3D ray. In this case, only the first result is returned.
This function returns a RaycastHit2D object with a reference to the Collider2D 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.
Additionally, this will also detect collider(s) at the start of the ray. In this case, the ray starts inside the collider and doesn't intersect the collider surface. This means that the collision normal cannot be calculated, in which case the returned collision normal 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: PhysicsScene2D class, RaycastHit2D class, Physics2D.DefaultRaycastLayers, Physics2D.IgnoreRaycastLayer, Physics2D.queriesHitTriggers.
| ray | 定义要测试的原点和方向的 3D 射线。 |
| distance | 光线的最大投射距离。 |
| results | 用于接收结果的数组。该数组的大小决定可返回的结果的最大数量。 |
| layerMask | 过滤器，用于仅在特定层上检测碰撞体。 |
int 返回的结果数量。
Cast a 3D ray against the colliders in the PhysicsScene2D, returning all intersections.
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. Raycasts are useful for determining lines of sight, targets hit by gunfire and for many other purposes in gameplay.
Unlike Raycast which performs a 2D intersection test, this function performs a 3D intersection test on 2D colliders. It does this by projecting the 3D ray into 2D space then performs the 2D intersection test, ordering the results by the Z direction of the original 3D ray.
This function returns any Collider2D that intersect the 3D ray with the results returned in the supplied array. The integer return value is the number of objects that intersect the line (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. Note that you will always get zero results if you pass an empty array.
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.
Additionally, this will also detect collider(s) at the start of the ray. In this case, the ray starts inside the collider and doesn't intersect the collider surface. This means that the collision normal cannot be calculated, in which case the returned collision normal 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.
All results are sorted by ascending distance order.
See Also: PhysicsScene2D class, RaycastHit2D class, Physics2D.DefaultRaycastLayers, Physics2D.IgnoreRaycastLayer, Physics2D.queriesHitTriggers.