Where/how is the ECI/ECEF rotation modelled?

[Ictogan1]

Hello,
I was looking through Basilisk and was wondering where the rotation between ECEF and ECI(or other internal-frame fixed-frame rotations) is done. I couldn't find this anywhere in the source files, although I am likely just looking in the wrong places. In particular whether it is rotated as a simple rotation around one axis or if it also accounts for polar motion and precession/nutation.

[Ictogan1]

Update: looked through basilisk more and found out that it is done using SPICE. However, none of the examples using the magneticFieldWMM seem to connect the planetPosInMsg. Am I correct in assuming that this means none of the examples have a correctly oriented magnetic field?

[schaubh]

That is correct, the scenario on using the WMM magnetic field talks about this optional input message.