Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for imaging scenes of three-dimensional (3-D) environments using a virtual reality system. A request to display a target three-dimensional environment in a virtual reality system is received. An image of a scene of the target three-dimensional environment is generated. The image of the scene includes features distributed within the scene of the target three-dimensional environment according to a distance from a viewing point of the scene of the target three-dimensional environment. A request to display a modified image of the scene of the target three-dimensional environment is received. The modified image of the scene of the target three-dimensional environment is generated by adding auxiliary data associated with the plurality of features relative to the distance from the viewing point of the scene of the target three-dimensional environment to each of the plurality of features.