Rotating by (-1,-1,-1) and then (1,1,1) results in movement???

If I do this,

transform.Rotate(1,1,1);
transform.Rotate(-1,-1,-1);

The object rotates on every axis by a tiny amount.
What causes this?

 

Probably accumulated floating point error.

If you really wanna have your mind blown, try mixing and matching rotating and parenting and deparenting each frame... you'll make objects swell or shrink or do all kinds of weird things as their transform matrices get all out of normal.

Always best to construct the rotation you want explicitly with Quaternion.Euler(x,y,z) each frame, then track the x,y,z yourself.

 

Well, seems like this works then.

Code (CSharp):

1. var temp_rot = Quaternion.Euler(1f, 1f, 1f);
2. transform.rotation = transform.rotation * temp_rot;
3. transform.rotation = transform.rotation * Quaternion.Inverse(temp_rot);

 

It works on your local rotation. The second one spins you (-1,-1,-1) on your _new_ xyz axis. Try it with larger numbers and you'll see move and more of a difference.