I think after various attempts that the source tree from portsnap needs to be downloaded and also you need to edit rc.conf and bootloader.conf ( I think the last one is wrong it boot something .conf and has it's own folder)
and adjust from nvidia_load= "YES" to Nvidia-modeset_load="YES"
Capitalisation is very important!!!
you must also do module load in rc.conf in the etc directory of root
Anyways, you get 2D desktop, but no GLX for gaming....with with previous configuration (nvidia_load "YES" in rc.conf or bootloader.conf)
I just did this and already forgot full details......curse you bad diet!
ASX, Ericbsd please edit bad or confusing Technical details .... kris moore did this in 12 CURRENT I thought it did not apply here but IT DOES!!!