A system for tracking a hand-held controller relative to a head mounted display, HMD, comprising: the hand-held controller; the HMD configured to be worn on a head of a user, wherein the HMD is configured to display a plurality of image scenes having content generated by execution of an application, wherein the HMD has a lower region having a camera, wherein the camera has a capture view directed downward from the HMD, wherein the camera is configured to capture a plurality images of the hand-held controller; and a processing device (112, 116) associated with the HMD for receiving a plurality of images of a real-world environment surrounding the HMD and the plurality of images of the hand-held controller, wherein the processing device is configured to determine a position and movement of the HMD within the real-world environment from the plurality of images of the real-world environment, wherein the processing device is configured to determine a position of the hand-held controller relative to the HMD from the plurality of images of the hand-held controller, wherein the processing device is configured to modify a state output by execution of the application according to the position and movement of the HMD and changes in the position of the hand-held controller, wherein the HMD is configured to update the plurality of image scenes displayed in the HMD according to the modification of the state, wherein the HMD has an additional camera on a side region of the HMD, wherein the additional camera has a capture view different from the capture view of the camera of the lower region, wherein the additional camera is configured to capture an additional plurality of images of a position and movement of the hand-held controller when the hand-held controller is outside the capture view of the camera of the lower region, wherein the processing device is configured to receive the additional plurality of images from the additional camera and stitch one of the additional plurality of images with one of the plurality of images received from the camera of the lower region to change the state. the hand-held controller; the HMD configured to be worn on a head of a user, wherein the HMD is configured to display a plurality of image scenes having content generated by execution of an application, wherein the HMD has a lower region having a camera, wherein the camera has a capture view directed downward from the HMD, wherein the camera is configured to capture a plurality images of the hand-held controller; and a processing device (112, 116) associated with the HMD for receiving a plurality of images of a real-world environment surrounding the HMD and the plurality of images of the hand-held controller, wherein the processing device is configured to determine a position and movement of the HMD within the real-world environment from the plurality of images of the real-world environment, wherein the processing device is configured to determine a position of the hand-held controller relative to the HMD from the plurality of images of the hand-held controller, wherein the processing device is configured to modify a state output by execution of the application according to the position and movement of the HMD and changes in the position of the hand-held controller, wherein the HMD is configured to update the plurality of image scenes displayed in the HMD according to the modification of the state, wherein the HMD has an additional camera on a side region of the HMD, wherein the additional camera has a capture view different from the capture view of the camera of the lower region, wherein the additional camera is configured to capture an additional plurality of images of a position and movement of the hand-held controller when the hand-held controller is outside the capture view of the camera of the lower region, wherein the processing device is configured to receive the additional plurality of images from the additional camera and stitch one of the additional plurality of images with one of the plurality of images received from the camera of the lower region to change the state.