A virtual environment browser (64) holds a number of clip-in files (70, 72, 74) defining guide characters—locally generated visual aids to navigation that appear within a generated image of a virtual environment and follow a user's input (80) navigational commands to provide an advance cue as to the effects of an input command. Where the virtual environment data is supplied from a remote source (62) and includes (78) an indication of a preferred mode for navigating that environment, for example, flying or walking, the browser (64) detects this indication and automatically selects the appropriate guide character. Scaling (84) of the guide character to match the scale of the virtual environment, or such as to render the guide character unobtrusive, may also be provided.