3D Representations: Difference between revisions

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===Light Field===
===Light Field===
This is similar to a collection of images.
This is similar to a collection of images.<br>
However, instead of thinking of it as a set of images, each pixel represents the color along a ray in 3D space.
However, instead of thinking of it as a set of images, each pixel represents the color along a ray in 3D space.<br>
Thus, light fields are collections of rays in 3D space. Typically we assume the rays lie in an empty/transparent space until they hit a surface.
Thus, light fields are collections of rays in 3D space which can be modeled using the plenoptic function <math>F: \mathbb{R}^5 \to \mathbb{R}</math>.<br>
See [[Light field]].
3-dimensions for the starting point of the ray and 2 dimensions for the direction of the ray.<br>
Typically we assume the rays lie in an empty/transparent space until they hit a surface thus rays can be models as lines which can be defined with 4 dimensions.<br>
See [[Light field]].<br>


===Volume===
===Volume===
A volume is a dense 3D dataset <math>F: \mathbb{R}^2 \to \mathbb{R}</math> where the value at each position <math>(x,y,z)</math> corresponds to a density.
A volume is a dense 3D dataset <math>F: \mathbb{R}^2 \to \mathbb{R}</math> where the value at each position <math>(x,y,z)</math> corresponds to a density.<br>
Volume rendering is used project a 3D volume into a 2D image by sampling the volume along a ray for each pixel in the 2D image.
Volume rendering is used project a 3D volume into a 2D image by sampling the volume along a ray for each pixel in the 2D image.<br>
Also known as a radiance field.


===Signed Distance Field===
===Signed Distance Field===