Light field
A light field, also known as a radiance field, is a volume of light where the light is measured by its angles as well as brightness. A light field represents light in a way that can be viewed naturally. It is segmented into rays that have direction, magnitude, and optionally color. It can be a volume of light treated as a set of rays, or a flat surface through which different angled light travels. Light fields allow for proper eye focus.
A light field is the set of light rays flowing through a surface or volume from every direction. It represents how light travels in physical space from a ray optics perspective. A light field can be viewed using a light field photograph. A light field can be displayed using a light field display, which is a type of multifocal display. It is possible to record a light field using a light field camera, such as a camera from Lytro.
One method of recording light fields is to use neural radiance field techniques.
Mathematics[edit]
There are multiple ways to represent a light field using data. A method is the two-plane method, which results in a 4D representation.
A light field can be black and white or full color.
Light fields can be represented using euclidean spatial representation, instead of having to use a relativistic understanding.
A light field can be represented using a plenoptic function, which is a 5 dimensional function. A partial light field can be represented in 4 dimensions using the two-plane method.[1] That can result in a 4-dimensional function. However, it may be limited in focal depth. Light fields are useful for 3D because the largest or second largest factor that determines focus is the angle of rays coming into a human eye.
History[edit]
Leonardo da Vinci explored the idea of a scene consisting of light rays of various angles.[2]
Light field photography was invented by Gabriel Lippman in the early 1900s. He called it integral photography.
The term "light field" was first used by Alexander Gershun in a research paper in about 1939.
From the 1960s to present, much of light field generation has been done using holograms to generate the light field. When most people talk about holograms, this is what they are referring to.
Work in light fields generated by a computer was done in the 1990s by Pat Hanrahan and Marc Levoy.[3]
Light field rendering research has focused on novel viewpoints for existing data, but largely for 2D screens.[4] Lumiscope VR pioneered light field software rendering in VR headsets with fixed focus from about 2015 to 2020, but did not release a commercial product.
References[edit]
- ↑ Gortler, Steven J.; Grzeszczuk, Radek; Szeliski, Richard; Cohen, Michael F. (1996). "The lumigraph". ACM. p. 43–54. doi:10.1145/237170.237200. ISBN 978-0-89791-746-9.
- ↑ http://lightfield-forum.com/2012/08/lightfield-history-who-invented-the-concept-of-the-light-field/
- ↑ "Light Field Rendering". http://www-graphics.stanford.edu/papers/light/.
- ↑ https://pages.cs.wisc.edu/~dyer/cs534/papers/levoy-light-field-tutorial.pdf