Unity2D raycast pointing at the wrong target - unity3d

Question

I am working on a script which makes a raycast going in the direction of the mouse. But for some reason it doesn't follow the mouse, it goes directly forward.
void Update()
{
if (Input.GetMouseButtonDown(0))
{
CastRay();
}
void CastRay()
{
Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
RaycastHit2D hit = Physics2D.Raycast(ray.origin, ray.direction, Mathf.Infinity);
if (hit.collider != null)
{
Debug.Log(hit.collider.gameObject.name);
}
}
}

Answer 1

The way I understand this question is that you'd like to cast a ray from the player position towards mouse position in 2D. If that is not the case then you should edit your question and give more context on what exactly you want to achieve.
When I understood correctly then the answer is that you construct the wrong ray. What you're doing is casting a ray from the cameras perspective, you can think of it as casting a ray through your monitor towards the game world.
To get a ray from the player characters perspective, the ray should be from the players position towards the mouse position in screen space.
// get the player position in screen space
var playerScreenSpacePosition = Camera.main.WorldToScreenPoint(playerPosition);
// calculate ray direction (to - from = direction)
var rayDirection = Input.mousePosition - playerScreenSpacePosition;
// if direction vectors length should be ignored then normalize
rayDirection.Normalize();
// construct the ray with the player being the origin
// (if needed could be Ray2D as well by ignoring 'Z' axis, needs converting position and direction to Vector2)
var ray = new Ray(playerPosition, rayDirection);
// cast for a hit
var hit = Physics2D.Raycast(ray.origin, ray.direction, Mathf.Infinity);
// alternatively: if the length of the raycast shall be defined by the directions magnitude
// (only if direction not normalized, otherwise the rays length will always be one)
hit = Physics2D.Raycast(ray.origin, ray.direction, ray.direction.magnitude);