Before revision:  By conducting user experiments and comparing the system with a conventional 2D-display daylight analysis tool , Diva4Rhino, the results show that RadVR outperforms Diva4Rhino in spatial understanding tasks, navigation  and sun position analysis  .
After revision:  By conducting user experiments and comparing the system with a conventional 2D-display daylight analysis tool , Diva4Rhino, the results show that RadVR can provide promising assistance in spatial understanding tasks, navigation and sun position analysis .