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{{see also|Terms|Technical Terms}}
{{see also|Terms|Technical Terms}}
'''Light Field Display''' (LFD) is an advanced visualization 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. “Computational Displays.” SIGGRAPH 2020 Course Notes</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>
'''Light Field Display''' (LFD) is an advanced visualization technology designed to reproduce a [[light field]], the distribution of light rays in [[3D space]], including their intensity and direction.<ref name="WetzsteinPlenoptic">G. Wetzstein, “Computational Displays: Achieving the Full Plenoptic Function,ACM SIGGRAPH 2020 Courses, Association for Computing Machinery, 2020. Available: https://s2020.siggraph.org/program/?sess=computational-displays-achieving-the-full-plenoptic-function (accessed 30 Apr 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 technology is considered 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">Zhang, Z., Yan, X., Zhang, Y., Liu, Y., & Peng, Y. (2021). Vergence-accommodation conflict in optical see-through display: review and prospect. Opto-Electronic Advances, 4(9), 210003. doi:10.29026/oea.2021.210003</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 HMDs.<ref name="XinRealityWiki">Near-eye light field display - XinReality Wiki. Retrieved from https://xinreality.com/wiki/Near-eye_light_field_display</ref><ref name="CrealWebsite">CREAL. Light-field: Seeing Virtual Worlds Naturally. Retrieved from https://creal.com/technology/</ref>
This technology is considered 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 HMDs.<ref name="XinRealityWiki">Near-eye light field display - XinReality Wiki. Retrieved from https://xinreality.com/wiki/Near-eye_light_field_display</ref><ref name="CrealWebsite">CREAL. Light-field: Seeing Virtual Worlds Naturally. Retrieved from https://creal.com/technology/</ref>


== Definition and Principles ==
== Definition and Principles ==
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* '''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:''' 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"/>
* '''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.<ref name="LeiaVerge"/>
* '''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="XinRealityWiki"/><ref name="CrealWebsite"/><ref name="Lanman2020NearEyeCourse">Lanman, D., & Luebke, D. (2020). Near-Eye Light Field Displays for VR and AR. SIGGRAPH Courses.</ref>
* '''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="XinRealityWiki"/><ref name="CrealWebsite"/><ref name="Lanman2020NearEyeCourse">D. Lanman and D. Luebke, “Near-Eye Light Field Displays for Virtual and Augmented Reality,” ACM SIGGRAPH 2020 Courses, Association for Computing Machinery, 2020. Available: https://s2020.siggraph.org/program/?sess=near-eye-light-field-displays (accessed 30 Apr 2025).</ref>
* '''Computational Requirements:''' Generating and processing the massive amount of data (multiple views or directional light information) needed for LFDs requires significant [[Graphics processing unit|GPU]] power and bandwidth.<ref name="LeiaVerge"/><ref name="Huang2014EyeglassesFree"/>
* '''Computational Requirements:''' Generating and processing the massive amount of data (multiple views or directional light information) needed for LFDs requires significant [[Graphics processing unit|GPU]] power and bandwidth.<ref name="LeiaVerge"/><ref name="Huang2014EyeglassesFree"/>
* '''Resolution Trade-offs:''' A fundamental challenge involves balancing spatial resolution (image sharpness), angular resolution (smoothness of parallax/number of views), [[Field of view|field of view (FoV)]], and depth of field.<ref name="Huang2014EyeglassesFree"/><ref name="Lanman2020NearEyeCourse"/> This is often referred to as the spatio-angular resolution trade-off.
* '''Resolution Trade-offs:''' A fundamental challenge involves balancing spatial resolution (image sharpness), angular resolution (smoothness of parallax/number of views), [[Field of view|field of view (FoV)]], and depth of field.<ref name="Huang2014EyeglassesFree"/><ref name="Lanman2020NearEyeCourse"/> This is often referred to as the spatio-angular resolution trade-off.
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* '''[[Waveguide]] Optics:''' Light is injected into thin optical waveguides (similar to those in some AR glasses) and then coupled out at specific points with controlled directionality, often using diffractive optical elements (DOEs) or gratings.<ref name="LightFieldLabTech">Light Field Lab. SolidLight Platform. Retrieved from https://www.lightfieldlab.com/solidlight</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.
* '''[[Waveguide]] Optics:''' Light is injected into thin optical waveguides (similar to those in some AR glasses) and then coupled out at specific points with controlled directionality, often using diffractive optical elements (DOEs) or gratings.<ref name="LightFieldLabTech">Light Field Lab. SolidLight Platform. Retrieved from https://www.lightfieldlab.com/solidlight</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:''' 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">Martínez-Corral, M., Guan, Z., Li, Y., Xiong, Z., & Javidi, B. (2021). Review of light field technologies. Visual Computing for Industry, Biomedicine, and Art, 4(1), 29. doi:10.1186/s42492-021-00096-8</ref> Some companies use "holographic" terminology for their high-density LFDs.<ref name="LightFieldLabHolographic">IEEE Spectrum (2021, October 7). Light Field Lab Claims to Have Cracked the Code for Real Holograms. Retrieved from https://spectrum.ieee.org/light-field-lab-holograms</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="LightFieldLabHolographic">IEEE Spectrum (2021, October 7). Light Field Lab Claims to Have Cracked the Code for Real Holograms. Retrieved from https://spectrum.ieee.org/light-field-lab-holograms</ref>


== Types of Light Field Displays ==
== Types of Light Field Displays ==