How can I prevent 2D teleportation from teleporting through solid objects?

Question

In my 2D game, the player is able to teleport to any place on the screen with the click of the mouse button. What I am trying to prevent is the ability to teleport across solid objects. If the point from the player and the mouse click position is across an object then I want the player to teleport next to that object instead of across it.

I am currently trying to achieve this with raycasting. The code I wrote somewhat works but only if the mouse click is on an object, if the mouse click is across another object, it still teleports me accross the object without it registering that there is an object between the player and the mouse position.

My code:

Vector3 player_position = Camera.main.WorldToScreenPoint(transform.position);
Vector3 to_object_vector = transform.position - Camera.main.transform.position;
Vector3 linear_distance_vector = Vector3.Project(to_object_vector, Camera.main.transform.forward);

float distance_to_camera = linear_distance_vector.magnitude;
Vector3 mouse_position = Input.mousePosition;
float dist = Vector2.Distance(player_position, mouse_position);
Vector3 dir = (mouse_position - player_position).normalized;
mouse_position.z = distance_to_camera;

RaycastHit2D hit = Physics2D.Raycast(new Vector2(player_position.x, player_position.y), new Vector2(dir.x, dir.y), dist, 0);
if (hit.collider != null) {
     Debug.Log(hit.point);
     mouse_position = new Vector3(hit.point.x, hit.point.y, mouse_position.z);
}

Is there a better approach to this problem?

Answer 1

One thing you should do, and this is useful for all of your Unity projects, is using Debug.DrawLine (if you have origin and destination) or Debug.DrawRay if you only have the direction vector.

I haven't used 2D mode in Unity, but I guess you can still use 3D in Scene inspector, right? If so, then use the functions above to throw rays from player to the hit.point position. You should do it into Update function, since it could draw a ray just for 1 frame if you don't and you wouldn't see it.

Things to check if working properly:

1. Check if the ray is drawing always trough the object when you click behind it, if it does, then you're not setting the nearest position properly.
2. Check that those objects you don't want to go through are not in a Ignore raycast layer.

Now, talking about how to move your character, I would try to use Physics AddForce. Even though it is 3D, you can just use 0 into x/z axis and use Physics to move character. If you multiply the vector for a high thrust, I think you could get a teleport simulation (deactivating MeshRenderer before doing it, for example). Remember you need a Rigidbody to use that physics, and probably need to mark it as Kinetic in order to avoid it bouncing.

Hope this helps you.

Answer 2

Well since raycasting cannot solve my specific issue which is unfortunate, since it should return the end point of any solid objects that interrupts that line I was forced to expand my colliders far enough to where the player can't click over the object like so:

Since my if statement is checking if the player is clicking on a collider I will always teleport to the hit.point preventing the player from going outside the map indefinitely!