# Rotate a KinematicCharacter3D towards another object in only one axis?

Attention Topic was automatically imported from the old Question2Answer platform.

I want to rotate a KinematicCharacter3D towards another one, rotating only one axis. I know I can use rotate_y() for what I want, but I don’t understand how to calculate the direction and angle so that it will rotate towards another enemy.

I tried the look_at() function but it is buggy for what I want at least in my project. Anyone?

You’ll need a little math for that.

so first you’ll get the difference of the 2d vectors of the objects (x and y for example)

then, you need to get the arc tangent of the value you got previously

it would look something like this:

``````var a = Vector2(200, 600)
var b = Vector2(300, 100)
func getangle():
var diff = Vector2(a.x - b.x,a.y - b.y) #or can just be a - b but can be bothered to check
return atan(diff.y,diff.x) #return angle in radians. use radtodeg() if you want the angle in degrees.
``````

the vectors used will be the axis that isnt the axis of rotation. example:
getting y rotation using x and z vectors from both objects.

after that, set the bodies rotation.someaxis to getangle!

So in this case I need to get the global_transform.origin.x and global_transform.origin.z of the nodes I want, is this it? With a being the target node position and b being the node position itself?

I had to use atan2 cause atan only asked for 1 argument, but it doesn’t rotate right still.

Code:

``````var a = Vector2(locked_on_enemy.get_global_transform().origin.x, locked_on_enemy.get_global_transform().origin.z)
var b = Vector2(global_transform.origin.x, global_transform.origin.z)

rotation.y = getangle(a, b)

func getangle(a: Vector2, b: Vector2):
var diff = Vector2(a.x - b.x,a.y - b.y) #or can just be a - b but can be bothered to check
return atan2(diff.y,diff.x) #return angle in radians. use radtodeg() if you want the angle in degrees.
``````

Zero | 2020-06-21 17:24

yeah! that should work. be sure to actually set the rotation of the object.

dustin | 2020-06-22 05:08

umm he was asking for 3D not 2D is it gonna work for 3D too?

biraj | 2021-11-06 06:24