unity屏幕射线

Physics类的Raycast可以发射射线，具体可以参考官方文档以下是一个简单的屏幕2D射线

Vector3 mousePos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
Vector2 mousePos2D = new Vector2(mousePos.x, mousePos.y);
RaycastHit2D hit = Physics2D.Raycast(mousePos2D, Vector2.zero);
Debug.Log(hit.collider);