349
edits
Changes
no edit summary
NVIDIA showed a revision of its light field prototype during the Virtual Reality LA Expo of 2016, in Southern California. The unit was attached to a desktop PC equipped with a Maxwell-based GPU. To compute the light fields images in real-time, NVIDIA used an algorithm based on its CUDA parallel programming language for GPUs. Still in collaboration with Stanford University, the new prototype eliminates the headphone requirement with a VR headset design that does not produce motion sickness side effects. The light field stereoscope uses two layered displays with back-to-back LCD panels. These are in-between a backlight and two circular viewing lenses (Figure 5). The device creates a natural depth-of-field in each eye, combining it with a stereoscopic technique (showing images at slightly different angles in each eye) <ref name=”10”> Worrel, J. (2016). Nvidia shows off its 'Light Field' VR headset at VRLA 2016. Retrieved from http://www.fudzilla.com/news/graphics/39762-nvidia-shows-off-its-light-field-vr-headset-at-vrla-2016</ref>.
==Main characteristics of near-eye light field displays==
The main benefits of the near-eye light field displays are reduced thickness and weight. In the 2013 prototype this was achieved by substituting a compact microlens array for compound magnifying optics. Adding to this, the device addresses the accommodation-convergence conflict with binocular configurations by approximating retinal defocus blur. It also accounts for the user’s glasses or contact prescription through software <ref name=”2”></ref> <ref name=”5”></ref>.
On the other hand, reduced spatial resolution was the primary limitation of this device. Lanman and Luebke (2013) indicate that the resolution is proportional to the ratio of the microlens focal length to the distance of the display from the eye, creating tension between compact form factors and higher resolutions. Furthermore, they wrote that “practical applications will necessitate manufacturing larger microdisplays with smaller pixel pitches, enabling wide fields of view and high resolutions, respectively.” <ref name=”2”></ref>
The near-eye light field stereoscope prototype of 2015 also addresses the accommodation-convergence conflict that leads to motion sickness, resulting in a more natural and flexible experience. In this case, the device uses two layers of LCD separated by approximately 5 millimeters. These send an entire “4D” light field of images so the eye can set focus between objects more naturally <ref name=”11”> Pirzada, Usman (2015). Nvidia Working On Next Generation Virtual Reality Device; The Near Eye Light Field Stereoscope, Aims To Bring It To The Market by 2018. Retrieved from http://wccftech.com/nvidia-virtual-reality-device-light-field-2018/</ref>.
The resolution was also a limitation in this prototype. While the screen resolution was 1280x800, the HMD splits the screen into two halves, making the effective resolution decrease to 640x800 per eye. This is too low for a current setting, but it could be improved in the future since this is still in the prototype stage. Indeed, NVIDIA intends to bring this device into the market by 2018. While NVIDIA could be developing the new standard for HMDs, it could also mean that by the time the device is released to the market conventional VR makers may have solved the problems related to motion sickness in their own devices <ref name=”11”></ref>.
==References==
