How to rotate the X and Y-axis, while fixing the Z-axis

Unity Engine
1

Hi Experts,

I want to rotate the X and Y-axis, while fixing the Z-axis.

Test implementation is the below.

Update()
{
    transform.Rotate(Time.deltaTime, Time.deltaTime, 0, Space.World)
}

I found that transform,eularAngles.z changes zero to another value gradually.
(My expectation is transform,eularAngles.z always zero.)

Please tell me how to rotate the X and Y-axis, while fixing the Z-axis.

Thanks,
Akira Ueda

Transform.Rotate

Transform.eulerAngles

2

This has been asked millions of times, a quick google search will give you lots of answers:

3

Why does eularAngles.z change even if transform.Rotate(dx, dy, 0)?

4

Can you tell me what value it changes to? Quaternions and eulers are weird, and there is probably floating point imprecisions when the conversion is being done. Is the value jumping back and forth somewhere between 359 and 1? That might just be normal.