| sp | 屏幕点。 |
| eventCamera | 摄像机。 |
bool 如果提供的点是进行 GraphicRaycaster 射线投射的有效位置，则为 true。
When a GraphicRaycaster is raycasting into the Scene it does two things. First it filters the elements using their RectTransform rect. Then it uses this Raycast function to determine the elements hit by the raycast.