How To Make it Aim in Right Direction?

[CunningLobster]

Hi! I try to make a shooting system in my game and I can’t figure out how to make my character aim in right direction.

Weird aiming

As you can see in the video above a red line, which represents the aiming direction, doesn’t match a mouse position. To achieve the result I just rotated the gun around Z axis using such expression:

gun.transform.rotation = Quaternion.Euler(0, 0, touchControlsManager.TouchPosition().y);

But It doesn’t work fine. Could somebody help me to calculate the aiming direction according a mouse position?

[Lekret]

Your code is wrong. If you have your weapon in let’s say (0, 0) point, then if your touch position is (1, 1), then the result angle should be 45 angles relative to the ground. Then let’s say you move your mouse in (2, 2) point, angle should still be 45 angles, but in your case it would different, world positions have nothing to do with euler angles which is simple 360 angle system.
In your case you need something like:

transform.LookAt(mousePosition)

[CunningLobster]

@Lekret

Your code is wrong. If you have your weapon in let’s say (0, 0) point, then if your touch position is (1, 1), then the result angle should be 45 angles relative to the ground. Then let’s say you move your mouse in (2, 2) point, angle should still be 45 angles, but in your case it would different, world positions have nothing to do with euler angles which is simple 360 angle system.
In your case you need something like:

transform.LookAt(mousePosition)

Unfortunately such expression is not relevant for me because LooAt oriented to Z axis. But I started searching for LookAt for Vector2 and found that solution:

@LiterallyJeff

You can use LookAt but you have to understand what it does, and what parameters it expects in order to get the result you want.

All the “Look” functions will be assuming that your object’s “forward” is the Z axis, as is the standard for 3D objects in Unity. Given a position, they will orient your object with the Z axis facing it.

For 2D objects, the “forward” axis is usually the X axis. The Z axis is pointing forward along the World Space Z axis so it appears flat to the camera as the sprite moves around on the XY plane. We don’t want that to change.

So instead we can use Quaternion.LookRotation, which accepts the Z and Y axis. We can tell it exactly which direction the Z and Y axis should face, which will result in the X axis pointing where we want.

public void LookAt2D(Vector3 lookTarget)
{
    // the direction we want the X axis to face (from this object, towards the target)
    Vector3 xDirection = (lookTarget - transform.position).normalized;

    // Y axis is 90 degrees away from the X axis
    Vector3 yDirection = Quaternion.Euler(0, 0, 90) * xDirection;

    // Z should stay facing forward for 2D objects
    Vector3 zDirection = Vector3.forward;

    // apply the rotation to this object
    transform.rotation = Quaternion.LookRotation(zDirection, yDirection);
}