# [SOLVED] Getting Y rotation as 0 - 360 degrees (or -180 to 180)

Hi I’d like to get the Y rotation of an object in 0 - 360 (or -180 to 180) but it only goes from -90 to 90 then the X and Z rotation jump from 0 to 180 or -180. This can also be seen in the editor.

To get the global Y rotation (rotation around the world Y axis) is pretty straightforward. It’s just an atan2 of the forward vector:

``````    var _transformedForward = new pc.Vec3();
pc.util.getYaw = function (quat) {
var transformedForward = _transformedForward;
quat.transformVector(pc.Vec3.FORWARD, transformedForward);

};
``````

If you need to get the local Y rotation, that is a little trickier because you have to take the parent and hierarchy into consideration.

1 Like

Sorry I’m new to coding in PlayCanvas…

This was my old code:

``````var e = this.rotationSource.getEulerAngles();
yaw = e.y;
``````

I was wondering how to use your code to get the degrees for the rotationSource entity… thanks!

``````    var _transformedForward = new pc.Vec3();
SomeScript.prototype.getYaw = function (quat) {
var transformedForward = _transformedForward;
quat.transformVector(pc.Vec3.FORWARD, transformedForward);

};

SomeScript.prototype.someFunction = function() {
var yaw = this.getYaw(this.rotationSource.getRotation());
// Some other code
}
``````
2 Likes

Thanks for your solution. It’s the only one I’ve found to rotate an object around it’s y-axis correcly and get the right Euler Angle. I’m using this calculated `yaw` angle now to create a quaternion rotation like this:

``````var rotQuat = pc.Quat();
rotQuat.setFromEulerAngles(0.0 , yaw, 0.0);
``````

The code for setFromEulerAngles is:

``````/**
* @function
* @name pc.Quat#setFromEulerAngles
* @description Sets a quaternion from Euler angles specified in XYZ order.
* @param {Number} ex Angle to rotate around X axis in degrees.
* @param {Number} ey Angle to rotate around Y axis in degrees.
* @param {Number} ez Angle to rotate around Z axis in degrees.
* @returns {pc.Quat} Self for chaining.
* @example
* var q = new pc.Quat();
* q.setFromEulerAngles(45, 90, 180);
*/
function setFromEulerAngles(ex, ey, ez) {
var sx, cx, sy, cy, sz, cz, halfToRad;

sx = Math.sin(ex);
cx = Math.cos(ex);
sy = Math.sin(ey);
cy = Math.cos(ey);
sz = Math.sin(ez);
cz = Math.cos(ez);

this.x = sx * cy * cz - cx * sy * sz;
this.y = cx * sy * cz + sx * cy * sz;
this.z = cx * cy * sz - sx * sy * cz;
this.w = cx * cy * cz + sx * sy * sz;

return this;
}
``````

I’ve found it in the forum somewhere, but it works!

I have to admit, that I don’t get it but thanks again for your code (I even don’t get the problem, cause i’ve never had this problem in other game engines before).

1 Like