A system, comprising: a 3D display device, comprising: a display panel mounted on a moving body in which a user is configured to be, the display panel being configured to display a parallax image to the user; an optical element configured to define a propagation direction of image light emitted from the display panel; a communication module configured to receive a motion signal indicating a parameter of a motion of the moving body, the parameter including acceleration of the moving body; and a controller configured to cause the display panel to display the parallax image according to positions of eyes of the user obtained based on the parameter indicated by the motion signal; an imaging device having an imaging range configured to contain a face of the user; characterized in that the system further comprises a memory configured to store a table indicating correspondence between acceleration of the moving body in an inter-eye direction of the user and the positions of eyes of the user in the inter-eye direction, wherein the controller is configured to calibrate the table based on a difference between first positions of the eyes estimated based on a captured image generated by the imaging device and second positions of the eyes estimated based on the acceleration in the inter-eye direction indicated by the motion signal. a 3D display device, comprising: a display panel mounted on a moving body in which a user is configured to be, the display panel being configured to display a parallax image to the user; an optical element configured to define a propagation direction of image light emitted from the display panel; a communication module configured to receive a motion signal indicating a parameter of a motion of the moving body, the parameter including acceleration of the moving body; and a controller configured to cause the display panel to display the parallax image according to positions of eyes of the user obtained based on the parameter indicated by the motion signal; a display panel mounted on a moving body in which a user is configured to be, the display panel being configured to display a parallax image to the user; an optical element configured to define a propagation direction of image light emitted from the display panel; a communication module configured to receive a motion signal indicating a parameter of a motion of the moving body, the parameter including acceleration of the moving body; and a controller configured to cause the display panel to display the parallax image according to positions of eyes of the user obtained based on the parameter indicated by the motion signal; an imaging device having an imaging range configured to contain a face of the user; a memory configured to store a table indicating correspondence between acceleration of the moving body in an inter-eye direction of the user and the positions of eyes of the user in the inter-eye direction, wherein the controller is configured to calibrate the table based on a difference between first positions of the eyes estimated based on a captured image generated by the imaging device and second positions of the eyes estimated based on the acceleration in the inter-eye direction indicated by the motion signal.