Look At smoothly and Rotate in one axis only

Scripting
1

I’ve been browsing as much as I can looking for this, but none of the threads I find gets the job done.

I need to rotate an object to look at my target with a smooth transition and rotate on just one of it’s axis (the Z axis). The turret should stop to shoot, shoot, then look at the target again by just rotating on the Z axis.

I already have the timer and stuff, but when I try rotating the turret, I haven’t been able to lock the rotation on X and Y.

I’ve tried some solutions, but maybe I’ve been looking at this for too long now. I’d appreciate any suggestions.

2

you could try using the Quaterion.Lerp function:

http://docs.unity3d.com/Documentation/ScriptReference/Quaternion.Lerp.html

also have a look around the Quaternion script reference page. there are some functions that can be used to achieve the intended effect.

3

I have this on my Update() function.

lookTarget();
transform.rotation = Quaternion.Lerp(transform.rotation, anchorHelper.transform.rotation, Time.time * 0.01f);

Then my lookTarget is:

Vector3 point = target.position;
point = new Vector3(point.x, point.y, 0);
anchorHelper.transform.LookAt(point);

which is where I have the toggle to look and not loot while aiming (it’s just a timed condition)… The thing is, when my turret “looks”, it still rotates on X, and Y, not Z only. My helper rotates on Z only, but I don’t need it to look at the target all the time. So, not working yet :frowning:

4

Don’t use LookAt, that’ll mess things up.
I’ve had the same problem a while ago while building a turret which has two different components - a socket which basically should only rotate on the Y axis to face the player’s XZ coordinate (Y is ignored at that step, or better: it’s the same as the actual transform has) and then the gun component which should only smootly rotate towards the player’s Y coordinate by rotating on the X axis.

It was hard to find a way for this, and understanding Quaternions is not exactly the easiest thing in the world. :wink:

So here’s the full script I used:

void LookAtPlayer() {
	
	// get vector to player but take y coordinate from self to make sure we are not getting any rotation on the wrong axis
	Vector3 socketLookAt = new Vector3(playerPosition.x, movingSocket.position.y, playerPosition.z);
	
	// create rotations for socket and gun
	Quaternion targetRotationSocket = Quaternion.LookRotation(socketLookAt - movingSocket.position);
	Quaternion targetRotationGun = Quaternion.LookRotation(playerPosition - movingGun.position);
	
	// slerp rotations and assign
	movingSocket.rotation = Quaternion.Slerp(movingSocket.rotation, targetRotationSocket, Time.deltaTime * rotationSmoothingSocket);
	movingGun.rotation = Quaternion.Slerp (movingGun.rotation, targetRotationGun, Time.deltaTime * rotationSmoothingGun);
	
	// important: reset local euler angles rotation of gun to make sure that we are getting rotation only on one axis
	movingGun.localEulerAngles = new Vector3(movingGun.localEulerAngles.x, 0,0);
}

Once you know what to do, it’s fairly easy and looks simple enough.

So actually you just need to get a Vector3 which you can calculate a rotation to, do your Lerp/Slerp stuff and afterwards make sure that the rotation - in this case the local Euler angle(!) is reset.

Hope this helps.

1 Like
5

Thanks for your input Glockenbeat,

I’ve tried your solution, but haven’t been able to get it to work completely, my turret object turns 180 degrees only (like from 12 o’clock to 6 o’clock), I’m not sure if it could be related to the turret being attached to a parent GameObject.

Here’s the script:

Vector3 turretLookAt = new Vector3(target.position.x, target.position.y, transform.position.z);
Quaternion RotationGun = Quaternion.LookRotation(turretLookAt - transform.position);
transform.rotation = Quaternion.Slerp (transform.rotation, RotationGun, Time.deltaTime * 5.0f);
transform.localEulerAngles = new Vector3(transform.localEulerAngles.x, 0, 0);
1 Like
6

bump

7

I am facing a similar problem, if you or anyone got to solve it please let me know.

8

I don’t know if it helps you but I struggled with something like that myself some time ago (not necessarily the same though, see last post): http://forum.unity3d.com/threads/122958-Help-with-rotating-turret