A processor-implemented method, comprising: adjusting a virtual content object (361, 471, 472, 473, 771, 772, 773) based on a height-to-width (h/w) ratio of a shape (461, 462, 463) of the virtual content object projected onto a projection plane (350, 480, 780), wherein the adjusting of the virtual content object comprises: fitting the h/w ratio of the virtual content object to a target ratio designated for a reference distance; and/or setting one of points belonging to a space corresponding to the virtual content object as a reference point, setting a reference axis perpendicular to a direction axis oriented from a user toward the reference point, at the reference point, and rotating the virtual content object based on the reference axis, comprising: reducing an angle between a reference plane and a bottom surface of the virtual content object, in response to a distance between a viewpoint of a user and a physical position of the virtual content object decreasing; and increasing the angle between the reference plane and the bottom surface of the virtual content object, in response to the distance between the viewpoint of the user and the physical position of the virtual content object increasing; and visualizing the adjusted virtual content object on the projection plane. adjusting a virtual content object (361, 471, 472, 473, 771, 772, 773) based on a height-to-width (h/w) ratio of a shape (461, 462, 463) of the virtual content object projected onto a projection plane (350, 480, 780), wherein the adjusting of the virtual content object comprises: fitting the h/w ratio of the virtual content object to a target ratio designated for a reference distance; and/or setting one of points belonging to a space corresponding to the virtual content object as a reference point, setting a reference axis perpendicular to a direction axis oriented from a user toward the reference point, at the reference point, and rotating the virtual content object based on the reference axis, comprising: reducing an angle between a reference plane and a bottom surface of the virtual content object, in response to a distance between a viewpoint of a user and a physical position of the virtual content object decreasing; and increasing the angle between the reference plane and the bottom surface of the virtual content object, in response to the distance between the viewpoint of the user and the physical position of the virtual content object increasing; and fitting the h/w ratio of the virtual content object to a target ratio designated for a reference distance; and/or setting one of points belonging to a space corresponding to the virtual content object as a reference point, setting a reference axis perpendicular to a direction axis oriented from a user toward the reference point, at the reference point, and rotating the virtual content object based on the reference axis, comprising: reducing an angle between a reference plane and a bottom surface of the virtual content object, in response to a distance between a viewpoint of a user and a physical position of the virtual content object decreasing; and increasing the angle between the reference plane and the bottom surface of the virtual content object, in response to the distance between the viewpoint of the user and the physical position of the virtual content object increasing; and reducing an angle between a reference plane and a bottom surface of the virtual content object, in response to a distance between a viewpoint of a user and a physical position of the virtual content object decreasing; and increasing the angle between the reference plane and the bottom surface of the virtual content object, in response to the distance between the viewpoint of the user and the physical position of the virtual content object increasing; and visualizing the adjusted virtual content object on the projection plane.