I know what Quaternion.identity does, but I don’t understand what “identity” means in this context.
I’ve been wondering about this for several years now.
It’s named after the identity matrix.
Aaaaah perfect!
Thank you
This too but it’s all basically the same idea. You multiply something by identity and it comes out as it started.
“No transformation” Queternion. Same logic as identity matrix. In case of Quaternion it is 0, 0, 0, 1
? I would expect
1 0 0 0
0 1 0 0
0 0 1 0
0 0 0 1
…for an identity matrix. Why is it only one row?
Because it is a quaternion, not a matrix, and quaternion only has 4 components in it. (X, Y, Z, W in games, although in math papers it can be abcd, ijkr, and so on).
Identity transform - for a quaternion - is X=0, Y=0, Z=0, W=1.
When storing rotations, XYZ components store rotation axis scaled by factor of Sin(rotAngle/2), and W stores Cos(rotAngle/2). Because 0 degree angle has Cos==1, and Sin==0, we get 0, 0, 0, 1