Weird behavior when setting eulerAngles directly

Questions & Answers
1

Hello, I’m using following code to set object’s rotation in my custom (in-game) level editor:

Quaternion quat = LevEditGlobals.currentGO.transform.rotation;
					Vector3 rot = quat.eulerAngles;
					if (transformAxis == Axis.X){
						rot.x = float.Parse(this.GetComponent<InputField>().text,System.Globalization.CultureInfo.InvariantCulture.NumberFormat);
					}
					if (transformAxis == Axis.Y){
						rot.y = float.Parse(this.GetComponent<InputField>().text,System.Globalization.CultureInfo.InvariantCulture.NumberFormat);
					}
					if (transformAxis == Axis.Z){
						rot.z = float.Parse(this.GetComponent<InputField>().text,System.Globalization.CultureInfo.InvariantCulture.NumberFormat);
					}
					quat.eulerAngles = rot;
					
					LevEditGlobals.currentGO.transform.rotation = quat;

As you can see, first I get object’s current rotation, then I set specific items, based on values of specific variable. So far, so good.

The problem is that when I try to set last one (Z), the real thing that is being changed is rotation on Y axis for some reason (and yes, transformAxis equals Axis.Z). No points for guessing what happens when I trty to change Y rotation (it changes Y rotation, spoiler alert).

I guess problem rises from my use of euler angles, but I don’t know how to write it in quaternion code.

2

Instead of setting the eulerAngles directly try using Quaternion.Euler instead to get a Quaternion rotation from the Euler angles you want to rotate. With this method you should be able to avoid Gimbal Lock.

3

This is normal. If you hand-set variables in the Inspector, you’ll see the same thing (visible orientations is correct/smoothly changing, but values suddenly snap.)

You should be able to read more about it with a Search. The issue is that rotations aren’t stored in EulerAngles. Whenever you set rotation using them, it converts into proper Quaternion rotations, and throws away your x,y,z. When you read it back, you get a fresh conversion from Quaternions to eulerAngles. It’s like telling someone “half-past 2” and getting back “30 minutes till 3.”