An augmented reality system generates computer-mediated reality on a client device. The client device has sensors including a camera configured to capture image data of an environment and a location sensor to capture location data describing a geolocation of the client device. The client device creates a three-dimensional (3-D) map with the image data and the location data for use in generating virtual objects to augment reality. The client device transmits the created 3-D map to an external server that may utilize the 3-D map to update a world map stored on the external server. The external server sends a local portion of the world map to the client device. The client device determines a distance between the client device and a mapping point to generate a computer-mediated reality image at the mapping point to be displayed on the client device.