receiving a first input signal from a first user, and using the first input signal for animation of a first avatar representative of the first user in the 3D environment, wherein the animation of the first avatar is based at least in part on a first input mode through which the first input signal is received from the first user;

presenting the 3D environment to the first user and to a second user during a 3D session, wherein presentation of the 3D environment during the 3D session to the first user and to the second user is based on respective first output modes selected by the first user and by the second user, wherein a first appearance of the first avatar during the 3D session is based on a setting chosen by the first user for presentation of the first avatar in the 3D environment to the second user, and wherein the first output mode selected by the second user overrides the setting chosen by the first user for presentation of the first avatar, so as to present the first avatar to the second user with a second appearance during the 3D session that is different from the first appearance;

in response to a change in a physical location of the first user, changing an input mode of the first user from the first input mode to a second input mode;

in response to the change in the physical location of the first user, changing the first output mode selected by the first user from the first output mode to a second output mode that is usable in the changed physical location while the first output mode is disabled; and

in response to a change in a physical location of the second user, changing the first output mode selected by the second user from the first output mode selected by the second user to some other output mode that is usable in the changed physical location of the second user and further based on capabilities of a device of the second user.