| ray | 定义要测试的原点和方向的 3D 射线。 |
| distance | 射线的最大投射距离。 |
| layerMask | The LayerMask filter used to select which layers to detect Colliders for. |
| results | 用于接收结果的数组。 |
int The number of RaycastHit2D results returned.
Cast a 3D ray against the 2D Colliders in the Scene.
This function acts as a 3D "ray cast" but specifically designed to detect 2D Colliders. It achieved this by projecting the 3D ray into 2D space and then performs the 2D intersection test, ordering the results by the Z direction of the original 3D ray.