Visual Realism Enhances Realistic Response in an Immersive Virtual Environment - Part 2

Does realistic lighting in an immersive VR application enhance presence - that is, the participants´ feeling that they´re actually in the scene and behaving accordingly? Part 1 of this study indicated that presence is more likely with real-time ray tracing than with ray casting. However, that research couldn´t separate the effects of overall illumination quality from the dynamic effects of real-time shadows and reflections. In a new experiment, 20 people experienced a scene rendered with either global or local illumination. Both conditions included dynamically changing shadows and reflections. Illumination quality didn´t affect presence, so the earlier result must have been caused by dynamic shadows and reflections. Nevertheless, global illumination did result in greater plausibility - that is, participants were more likely to respond as if the virtual events were real. These results indicate that global illumination does affect participant responses and is worth the effort.