A computer comprising: a processor , wherein the processor is configured to: calculate (S16, S19) first coordinates in a first coordinate system of a three-dimensional object rendered in an extended reality space defined by the first coordinate system; calculate (S12, S15, S18) second coordinates in a second coordinate system different from the first coordinate system of a device (C2), wherein the device is tracked by a tracking system (T2) related to a setting of the second coordinate system; and calculate (S17, S20) a coordinate conversion equation that converts coordinates of the second coordinate system into coordinates of the first coordinate system based on the first coordinates and the second coordinates, in response to a predetermined operation (S14) by a user, wherein the computer is characterized in that the processor is further configured to: control (S11, S13) a display such that first information indicating a tilt of the three-dimensional object in the first coordinate system and second information indicating a tilt of the device in the second coordinate system indicated by a measurement result of an inertial measurement unit included in the device are displayed in the extended reality space together with the three-dimensional object. a processor , wherein the processor is configured to: calculate (S16, S19) first coordinates in a first coordinate system of a three-dimensional object rendered in an extended reality space defined by the first coordinate system; calculate (S12, S15, S18) second coordinates in a second coordinate system different from the first coordinate system of a device (C2), wherein the device is tracked by a tracking system (T2) related to a setting of the second coordinate system; and calculate (S17, S20) a coordinate conversion equation that converts coordinates of the second coordinate system into coordinates of the first coordinate system based on the first coordinates and the second coordinates, in response to a predetermined operation (S14) by a user, calculate (S16, S19) first coordinates in a first coordinate system of a three-dimensional object rendered in an extended reality space defined by the first coordinate system; calculate (S12, S15, S18) second coordinates in a second coordinate system different from the first coordinate system of a device (C2), wherein the device is tracked by a tracking system (T2) related to a setting of the second coordinate system; and calculate (S17, S20) a coordinate conversion equation that converts coordinates of the second coordinate system into coordinates of the first coordinate system based on the first coordinates and the second coordinates, in response to a predetermined operation (S14) by a user, wherein the computer is characterized in that the processor is further configured to: control (S11, S13) a display such that first information indicating a tilt of the three-dimensional object in the first coordinate system and second information indicating a tilt of the device in the second coordinate system indicated by a measurement result of an inertial measurement unit included in the device are displayed in the extended reality space together with the three-dimensional object. <EOS>