A system is provided, including: a head-mounted display (HMD), including, a plurality of retroreflectors, and a display device; an emitter/detector unit, including, an emitter configured to emit a scanning beam into an interactive environment, the scanning beam being configured to continuously trace a predefined scan pattern, and a detector configured to detect reflections of the scanning beam back to the HMD by each of the plurality of retroreflectors; a computing device, including, a processor configured to, for each retroreflector, determine a time at which the reflection occurred, wherein the time is used to determine a location or orientation of the HMD in the interactive environment, the computing device configured to generate a view of a virtual space based on the determined location or orientation of the HMD; wherein the display device of the HMD is configured to render the view of the virtual space.