Light field display: Difference between revisions - VR & AR Wiki - Virtual Reality & Augmented Reality Wiki

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~~{{see also|Terms|Technical Terms}}~~

'''Light field display''' ('''LFD''') is an advanced display technology designed to reproduce a [[light field]], the distribution of light rays in [[3D space]], including their intensity and direction.<ref name="WetzsteinPlenoptic">Wetzstein G. (2020). “Computational Displays: Achieving the Full Plenoptic Function.” ACM SIGGRAPH 2020 Courses. ACM Digital Library. doi:10.1145/3386569.3409414. Available: https://dl.acm.org/doi/10.1145/3386569.3409414 (accessed 3 May 2025).</ref> Unlike conventional 2D displays or [[stereoscopic display|stereoscopic 3D]] systems that present flat images or fixed viewpoints requiring glasses, light field displays aim to recreate how light naturally propagates from a real scene.<ref name="WetzsteinTensor">Wetzstein, G., Lanman, D., Hirsch, M., & Raskar, R. (2012). Tensor displays: Compressive light field synthesis using multilayer displays with directional backlighting. ACM Transactions on Graphics, 31(4), Article 80. doi:10.1145/2185520.2185576</ref> This allows viewers to perceive genuine [[depth]], [[parallax]] (both horizontal and vertical), and perspective changes without special eyewear. (in many implementations).<ref name="LeiaVerge">Hollister, S. (2024, January 19). Leia is building a 3D empire on the back of the worst phone we've ever reviewed. The Verge. Retrieved from https://www.theverge.com/24036574/leia-glasses-free-3d-ces-2024</ref>

'''Light field display''' ('''LFD''') is an advanced display technology designed to reproduce a [[light field]], the distribution of light rays in [[3D space]], including their intensity and direction.<ref name="WetzsteinPlenoptic">Wetzstein G. (2020). “Computational Displays: Achieving the Full Plenoptic Function.” ACM SIGGRAPH 2020 Courses. ACM Digital Library. doi:10.1145/3386569.3409414. Available: https://dl.acm.org/doi/10.1145/3386569.3409414 (accessed 3 May 2025).</ref> Unlike conventional 2D displays or [[stereoscopic display|stereoscopic 3D]] systems that present flat images or fixed viewpoints requiring glasses, light field displays aim to recreate how light naturally propagates from a real scene.<ref name="WetzsteinTensor">Wetzstein, G., Lanman, D., Hirsch, M., & Raskar, R. (2012). Tensor displays: Compressive light field synthesis using multilayer displays with directional backlighting. ACM Transactions on Graphics, 31(4), Article 80. doi:10.1145/2185520.2185576</ref> This allows viewers to perceive genuine [[depth]], [[parallax]] (both horizontal and vertical), and perspective changes without special eyewear (in many implementations).~~<ref name="LookingGlass27">Looking Glass Factory. Looking Glass 27″ Light Field Display. Retrieved from https://lookingglassfactory.com/looking-glass-27</ref>~~<ref name="LeiaVerge">Hollister, S. (2024, January 19). Leia is building a 3D empire on the back of the worst phone we've ever reviewed. The Verge. Retrieved from https://www.theverge.com/24036574/leia-glasses-free-3d-ces-2024</ref>

This method of display is crucial for the future of [[virtual reality]] (VR) and [[augmented reality]] (AR), because it ~~can directly address~~ the [[vergence-accommodation conflict]] (VAC).<ref name="WiredVAC">Zhang, S. (2015, August 11). The Obscure Neuroscience Problem That's Plaguing VR. WIRED. Retrieved from https://www.wired.com/2015/08/obscure-neuroscience-problem-thats-plaguing-vr</ref><ref name="VACReview">Y. Zhou, J. Zhang, F. Fang, “Vergence-accommodation conflict in optical see-through display: Review and prospect,” *Results in Optics*, vol. 5, p. 100160, 2021, doi:10.1016/j.rio.2021.100160.</ref> ~~By providing~~ correct [[focal cues]] that match the [[vergence]] information, ~~LFDs promise~~ more ~~immersive,~~ realistic~~, and~~ visually comfortable ~~experiences~~, reducing eye strain and [[Virtual Reality Sickness|simulator sickness]] often associated with current [[head-mounted display]]s (HMDs).<ref name="CrealWebsite">CREAL. Light-field: Seeing Virtual Worlds Naturally. Retrieved from https://creal.com/technology/</ref>

This method of display is crucial for the future of [[virtual reality]] (VR) and [[augmented reality]] (AR), because it solves the [[vergence-accommodation conflict]] (VAC).<ref name="WiredVAC">Zhang, S. (2015, August 11). The Obscure Neuroscience Problem That's Plaguing VR. WIRED. Retrieved from https://www.wired.com/2015/08/obscure-neuroscience-problem-thats-plaguing-vr</ref><ref name="VACReview">Y. Zhou, J. Zhang, F. Fang, “Vergence-accommodation conflict in optical see-through display: Review and prospect,” *Results in Optics*, vol. 5, p. 100160, 2021, doi:10.1016/j.rio.2021.100160.</ref> It provides correct [[focal cues]] that match the [[vergence]] information, giving a more realistic 3D image that is more visually comfortable, reducing eye strain and [[Virtual Reality Sickness|simulator sickness]] often associated with current [[head-mounted display]]s (HMDs).<ref name="CrealWebsite">CREAL. Light-field: Seeing Virtual Worlds Naturally. Retrieved from https://creal.com/technology/</ref>

== Definition and Principles ==

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* Natural [[focal cues]], mitigating the [[Vergence-accommodation conflict]].<ref name="WiredVAC"/>

* [[Specular highlights]] and realistic reflections that change with viewpoint.

* ~~Often, viewing~~ without specialized eyewear (especially in non-headset formats).~~<ref name="LookingGlass27"/>~~

* Viewing without specialized eyewear (especially in non-headset formats).

== ~~Key~~ Characteristics ==

== Characteristics ==

* '''Glasses-Free 3D:''' Many LFD formats (especially desktop and larger) offer autostereoscopic viewing for multiple users simultaneously, each seeing the correct perspective.<ref name="LookingGlass27"/><ref name="LeiaVerge"/>

* '''Glasses-Free 3D'''

* '''Full Parallax:''' True LFDs provide both horizontal and vertical parallax, unlike earlier [[autostereoscopic display|autostereoscopic]] technologies that often limited parallax to side-to-side movement.~~<ref name="LeiaVerge"/>~~

* '''Full Parallax:''' True LFDs provide both horizontal and vertical parallax, unlike earlier [[autostereoscopic display|autostereoscopic]] technologies that often limited parallax to side-to-side movement.

* '''Accommodation-Convergence Conflict Resolution:''' A primary driver for VR/AR, LFDs can render virtual objects at appropriate focal distances, aligning accommodation and vergence to significantly improve visual comfort and realism.<ref name="CrealWebsite"/><ref name="Lanman2020NearEyeCourse">

Lanman D., & Luebke D. (2013). “Near‑Eye Light Field Displays.”

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* '''2010-2013:''' Introduction of multilayer, compressive, and tensor light field display concepts.<ref name="Lanman2010ContentAdaptive">Lanman, D., Hirsch, M., Kim, Y., & Raskar, R. (2010). Content-adaptive parallax barriers: optimizing dual-layer 3D displays using low-rank light field factorization. ACM SIGGRAPH Asia 2010 papers (SIGGRAPH ASIA '10), Article 163. doi:10.1145/1882261.1866191</ref><ref name="WetzsteinTensor"/>

* '''2013:''' NVIDIA demonstrates near-eye light field display prototype for VR.<ref name="NvidiaNELD">Lanman, D., & Luebke, D. (2013). Near-Eye Light Field Displays (Technical Report NVR-2013-004). NVIDIA Research. Retrieved from https://research.nvidia.com/sites/default/files/pubs/2013-11_Near-Eye-Light-Field/NVIDIA-NELD.pdf</ref>

* '''2015 onwards:''' Emergence of advanced prototypes (for example ~~Sony,~~ CREAL, Light Field Lab).~~<ref name="LookingGlass27"/>~~<ref name="LeiaVerge"/><ref name="CrealRoadToVR">Lang, B. (2023, January 11). CREAL's Latest Light-field AR Demo Shows Continued Progress Toward Natural Depth & Focus. Road to VR. Retrieved from https://www.roadtovr.com/creal-light-field-ar-vr-headset-prototype/</ref>

* '''2015 onwards:''' Emergence of advanced prototypes (for example CREAL, Light Field Lab, PetaRay).<ref name="LeiaVerge"/><ref name="CrealRoadToVR">Lang, B. (2023, January 11). CREAL's Latest Light-field AR Demo Shows Continued Progress Toward Natural Depth & Focus. Road to VR. Retrieved from https://www.roadtovr.com/creal-light-field-ar-vr-headset-prototype/</ref>

== Technical Implementations (How They Work) ==

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Light Field Lab. *SolidLight™ Platform Overview.* https://www.lightfieldlab.com/ (accessed 3 May 2025).

</ref><ref name="Maimone2017HolographicNED">Maimone, A., Georgiou, A., & Kollin, J. S. (2017). Holographic near-eye displays for virtual and augmented reality. ACM Transactions on Graphics, 36(4), Article 85. doi:10.1145/3072959.3073624</ref> This is explored for compact AR/VR systems.

* '''Time-Multiplexed Displays:''' Different views or directional illumination patterns are presented rapidly in sequence. If cycled faster than human perception, this creates the illusion of a continuous light field. Can be combined with other techniques like directional backlighting.<ref name="Liu2014OSTHMD">Liu, S., Cheng, D., & Hua, H. (2014). An optical see-through head mounted display with addressable focal planes. 2014 IEEE International Symposium on Mixed and Augmented Reality (ISMAR), 33-42. doi:10.1109/ISMAR.2014.6948403</ref>

* '''Time-Multiplexed Displays:''' This is what CREAL is doing. Different views or directional illumination patterns are presented rapidly in sequence. If cycled faster than human perception, this creates the illusion of a continuous light field. Can be combined with other techniques like directional backlighting.<ref name="Liu2014OSTHMD">Liu, S., Cheng, D., & Hua, H. (2014). An optical see-through head mounted display with addressable focal planes. 2014 IEEE International Symposium on Mixed and Augmented Reality (ISMAR), 33-42. doi:10.1109/ISMAR.2014.6948403</ref>

* '''Holographic and Diffractive Approaches:''' While [[Holographic display|holographic displays]] reconstruct wavefronts through diffraction, some LFDs utilize holographic optical elements (HOEs) or related diffractive principles to achieve high angular resolution and potentially overcome MLA limitations.<ref name="SpringerReview2021">M. Martínez-Corral, Z. Guan, Y. Li, Z. Xiong, B. Javidi, “Review of light field technologies,” *Visual Computing for Industry, Biomedicine and Art*, 4 (1): 29, 2021, doi:10.1186/s42492-021-00096-8.</ref> Some companies use "holographic" terminology for their high-density LFDs.<ref name="ForbesLightField">C. Fink, “Light Field Lab Raises $50 Million to Bring SolidLight Holograms Into the Real World,” *Forbes*, 8 Feb 2023. Available: https://www.forbes.com/sites/charliefink/2023/02/08/light-field-lab-raises-50m-to-bring-solidlight-holograms-into-the-real-world/ (accessed 30 Apr 2025).</ref>

== Types of Light Field Displays ==

* '''Near-Eye Light Field Displays:''' Integrated into VR/AR [[Head-mounted display|HMDs]]. Primarily focused on solving the VAC for comfortable, realistic close-up interactions.<ref name="CrealWebsite"/><ref name="Lanman2020NearEyeCourse"/> Examples include research prototypes from NVIDIA<ref name="NvidiaNELD"/> and academic groups,<ref name="Huang2015Stereoscope">Huang, F. C., Chen, K., & Wetzstein, G. (2015). The light field stereoscope: immersive computer graphics via factored near-eye light field displays with focus cues. ACM Transactions on Graphics, 34(4), Article 60. doi:10.1145/2766943</ref> and commercial modules from companies like [[CREAL]].<ref name="CrealRoadToVR"/> Often utilize MLAs, stacked LCDs, or waveguide/diffractive approaches.<ref name="Lanman2020NearEyeCourse"/><ref name="CrealRoadToVR"/>

* '''Large Format / Tiled Displays:''' Aimed at creating large-scale, immersive ~~"holographic"~~ experiences without glasses for public venues, command centers, or collaborative environments.<ref name="ForbesLightField"/><ref name="LightFieldLabSolidLightPR">

* '''Large Format / Tiled Displays:''' Aimed at creating large-scale, immersive 3D experiences without glasses for public venues, command centers, or collaborative environments.<ref name="ForbesLightField"/><ref name="LightFieldLabSolidLightPR">

Light Field Lab Press Release (2021, Oct 7). *Light Field Lab Unveils SolidLight™ – The Highest Resolution Holographic Display Platform Ever Designed.*

https://www.lightfieldlab.com/press-release-oct-2021 (accessed 3 May 2025).

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! Key Trade-offs

|-

| '''[[Light Field Display]]'''

| '''Light Field Display'''

| No (often)

| Yes

| ~~Limited to Wide~~

|

| Spatio-angular resolution trade-off, computation needs

|-

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Creating content compatible with LFDs requires capturing or generating directional view information:

* '''[[Light Field Camera|Light Field Cameras]] / [[Plenoptic Camera|Plenoptic Cameras]]:''' Capture both intensity and direction of incoming light using specialized sensors (often with MLAs).<ref name="WetzsteinPlenoptic"/> The captured data can be processed for LFD playback.

* '''[[Computer Graphics]] Rendering:''' Standard 3D scenes built in engines like [[Unity (game engine)|Unity]] or [[Unreal Engine]] can be rendered from multiple viewpoints to generate the necessary data.<ref name="ForbesLightField~~"/><ref name="LookingGlassSoftware~~"/> Specialized light field rendering techniques, potentially using [[Ray tracing (graphics)|ray tracing]] or neural methods like [[Neural Radiance Fields]] (NeRF), are employed.<ref name="ForbesLightField"/><ref name="Mildenhall2020NeRF">Mildenhall, B., Srinivasan, P. P., Tancik, M., Barron, J. T., Ramamoorthi, R., & Ng, R. (2020). NeRF: Representing Scenes as Neural Radiance Fields for View Synthesis. European Conference on Computer Vision (ECCV), 405-421. doi:10.1007/978-3-030-58452-8_24</ref>

* '''[[Computer Graphics]] Rendering:''' Standard 3D scenes built in engines like [[Unity (game engine)|Unity]] or [[Unreal Engine]] can be rendered from multiple viewpoints to generate the necessary data.<ref name="ForbesLightField"/> Specialized light field rendering techniques, potentially using [[Ray tracing (graphics)|ray tracing]] or neural methods like [[Neural Radiance Fields]] (NeRF), are employed.<ref name="ForbesLightField"/><ref name="Mildenhall2020NeRF">Mildenhall, B., Srinivasan, P. P., Tancik, M., Barron, J. T., Ramamoorthi, R., & Ng, R. (2020). NeRF: Representing Scenes as Neural Radiance Fields for View Synthesis. European Conference on Computer Vision (ECCV), 405-421. doi:10.1007/978-3-030-58452-8_24</ref>

* '''[[Photogrammetry]] and 3D Scanning:''' Real-world objects/scenes captured as 3D models can serve as input for rendering light field views.

* '''Existing 3D Content Conversion:''' Plugins and software tools (for example provided by Looking Glass Factory) allow conversion of existing 3D models, animations, or even stereoscopic content for LFD viewing.<ref name="LookingGlassSoftware"/>

* '''[[Focal Stack]] Conversion:''' Research explores converting image stacks captured at different focal depths into light field representations, particularly for multi-layer displays.<ref name="WetzsteinTensor"/>

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* '''Medical Imaging and Visualization:''' Intuitive visualization of complex 3D scans (CT, MRI) for diagnostics, surgical planning, and education.<ref name="Nam2019Medical">Nam, J., McCormick, M., & Tate, A. J. (2019). Light field display systems for medical imaging applications. Journal of Display Technology, 15(3), 215-225. doi:10.1002/jsid.785</ref>

* '''Scientific Visualization:''' Analyzing complex datasets in fields like fluid dynamics, molecular modeling, geology.<ref name="Halle2017SciVis">Halle, M. W., & Meng, J. (2017). LightPlanets: GPU-based rendering of transparent astronomical objects using light field methods. IEEE Transactions on Visualization and Computer Graphics, 23(5), 1479-1488. doi:10.1109/TVCG.2016.2535388</ref>

* '''[[Digital Signage]] and Advertising:''' Eye-catching glasses-free 3D displays for retail and public spaces.<ref name="LookingGlass27"/>

* '''Product Design and Engineering (CAD/CAE):''' Collaborative visualization and review of 3D models.<ref name="Nam2019Medical"/>

* '''Entertainment and Gaming:''' Immersive experiences in arcades, museums, theme parks, and potentially future home entertainment.<ref name="ForbesLightField"/>

* '''Automotive Displays:''' [[Head-up display|Heads-up displays]] (HUDs) or dashboards presenting information at appropriate depths.<ref name="JDI_Parallax"/>

* '''Telepresence and Communication:''' Creating realistic, life-sized 3D representations of remote collaborators, like Google's [[Project Starline]] concept.<ref name="Starline">Google Blog (2023, May 10). A first look at Project Starline’s new, simpler prototype. Retrieved from https://blog.google/technology/research/project-starline-prototype/</ref>

* '''[[Microscopy]]:''' Viewing microscopic samples with natural depth perception.<ref name="WetzsteinPlenoptic"/>

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* '''Form Factor and Miniaturization:''' Integrating complex optics and electronics into thin, lightweight, and power-efficient near-eye devices remains difficult.<ref name="Lanman2020NearEyeCourse"/><ref name="CrealRoadToVR"/>

* '''Limited Field of View (FoV):''' Achieving wide FoV comparable to traditional VR headsets while maintaining high angular resolution is challenging.<ref name="Lanman2020NearEyeCourse"/>

* '''Brightness and Efficiency:''' Techniques like MLAs and parallax barriers inherently block or redirect light, reducing overall display brightness and power efficiency.

* '''Content Ecosystem:''' The workflow for creating, distributing, and viewing native light field content is still developing compared to standard 2D or stereoscopic 3D, due to no consumer lightfield hardware.

* '''Content Ecosystem:''' The workflow for creating, distributing, and viewing native light field content is still developing compared to standard 2D or stereoscopic 3D~~.<ref name="LookingGlassSoftware"/>~~

* '''Visual Artifacts:''' Potential issues include [[Moiré pattern|moiré]] effects (from periodic structures like MLAs), ~~ghosting/crosstalk between views, and latency~~.

== Key Players and Commercial Landscape ==

Several companies and research groups are active in LFD development:

* '''[[CREAL]]:''' Swiss startup focused on compact near-eye LFD modules for AR/VR glasses aiming to solve VAC.<ref name="CrealRoadToVR"/>

* '''[[Light Field Lab]]:''' Developing large-scale, modular ~~"holographic"~~ LFD panels (~~SolidLight™~~) based on ~~proprietary~~ [[Waveguide (optics)|waveguide]] technology.<ref name="LightFieldLabTech"/><ref name="LightFieldLabSolidLightPR"/>

* '''[[Light Field Lab]]:''' Developing large-scale, modular LFD panels (branded as SolidLight) based on [[Waveguide (optics)|waveguide]] technology.<ref name="LightFieldLabTech"/><ref name="LightFieldLabSolidLightPR"/>

* '''[[Sony]]:''' Produces the Spatial Reality Display (ELF-SR series), a high-fidelity desktop LFD using eye-tracking.<ref name="SonyELFSR2"/>

* '''[[Avegant]]:''' Develops light field light engines, particularly for AR, focusing on VAC resolution.<ref name="AvegantPR">PR Newswire (2017, March 15). Avegant Introduces Light Field Technology for Mixed Reality. Retrieved from https://www.prnewswire.com/news-releases/avegant-introduces-light-field-technology-for-mixed-reality-300423855.html</ref>