Rotate 2D missile in direction of flight?

[Selek-of-Vulcan]

I know this question has been asked many times, but I’ve tried many of the suggested solutions, and none seems to work properly for me. I’m making a top-down 2D game, and I’m trying to point a missile (a game object) at its target. The origin and target locations are fixed in world space. The missile moves in a straight line from origin to target, in Update(). But for the life of me, I can’t get it to point at the target. I’ve tried several approaches.

Vector2 direction = (zapTarget - zapOrigin).normalized;

float rotSpeed = 10f;

Quaternion toRotation = Quaternion.LookRotation(Vector3.forward, direction);

missile.transform.rotation = Quaternion.RotateTowards(attacker.missile.transform.rotation, toRotation, rotSpeed);

In place of that last line, I’ve also tried:
// missile.transform.rotation = toRotation;
and:

I’ve also tried the more complex code in this thread:

Look rotation 2d equivalent

Fantastic explanation. We were doing it all manually with Eulers before, but the looping around zero and 360 was getting funky. Thank you! This works perfectly.

No matter what I try, the missile faces in one incorrect direction and remains in that direction. Can anyone suggest a better approach? I have the nagging feeling there’s a much simpler solution, because the problem seems so basic to me. Thanks in advance.

[venediklee]

You can manually calculate the z angle:

var zAngle = Mathf.Atan2(direction .y, direction .x) * Mathf.Rad2Deg;
missile.transform.rotation = Quaternion.Euler(0,0,zAngle);

If your missles still dont face the correct rotation, it means your missile sprite is rotated or something.

Pretty sure there are solutions using the Quaternion class too:

Direction Vector to Euler/Quaternion

If you want the rotation to a certain Vector, you can do this in 2D: Vector3 direction = target - transform.position; transform.rotation = Quaternion.FromToRotation(Vector3.right, direction);

How to rotate object to align with vector?

I've a standard 2D game and need to align an object so its Y-axis faces a given vector. In theory I should use Quaternion.LookRotation() but it never works correctly. I created a little test scene and tried every option for the upwards vector, but the best result I've had still adds a 90 degrees twist on the Y axis. public class _test : MonoBehaviour { public Transform thing; public Vector2 dir; public Vector3 upwards; void Update(){ thing.rotation = Quaternion.LookRotatio…

Cheers

[Kurt-Dekker]

If your missile points UP, then just set the transform.up to your motion, as long as the motion is above a certain amount, something like:

if (movementVector.magnitude >= 0.05f)
{
  missileTransform.up = movementVector;
}

That’s it.

If your missile points right, then assign the movement to transform.right instead.

Or do the math with Atan2(), same end result really.

See my attached missile-chases-you game package.

9072451–1255234–MissileTurnTowards.unitypackage (12.1 KB)

[Selek-of-Vulcan]

Thanks, guys! I tried Atan2(), and it worked immediately. My sprite is facing right, for what it’s worth, so I didn’t have to make any adjustments at all to @venediklee 's suggested code. @Kurt-Dekker , I also will dig into your package, because I might eventually want the missile to do more than just fly in one direction.

Thanks again! I really appreciate all the help.