Methods and apparatus for determining location of objects surrounding a user of a 3D rendering and display system and indicating the objects to the user while the user views a simulated environment, e.g., on a headmounted display, are described. A sensor, e.g. camera, captures images or senses the physical environment where the user of the system is located. One or more objects in the physical environment are identified, e.g., by recognizing predetermined symbols on the objects and based on stored information indicating a mapping between different symbols and objects. The location of the objects relative to the user's location in the physical environment is determined. A simulated environment, including content corresponding to a scene and visual representations of the one or more objects, is displayed. In some embodiments visual representation are displayed in the simulated environment at locations determined based on the location of the objects relative to the user.