Yes, degrees of freedom, i suppose as421465683 refers to the description of two navigation modes in VR, with 3dof being three rotation axes, basically ‘sitting’ or ‘standing’ mode where the user can look around and 6dof with three additional translation axes as in ‘walking’ and climbing or flying, for that matter .
Regarding the question itself, hard to say, a combination of the ‘virtual reality’ demo navigation with the additions which kdv posted for 6dof. 3dof would require then locking the translation movement and adding a teleport feature, which i am unsure if it has been showcased on the forums.
About switching between these two – its a matter of personal preference, but i can’t imagine (yet) a scenario where you would like to switch between those, especially if you went all the way to implement 6dof navigation with raycast collisions or even physics collisions. Teleporting can help prevent the user from walking through walls by limiting teleport areas in a simpler way than using collisions with 6dof. (He can still walk through walls in VR if he chooses to physically walk, nothing except a physics collision system will prevent this, afaik).