Voxel: Exploring the Depths of Computer Vision with Voxel Technology

By Fouad Sabry

What is Voxel

In 3D computer graphics, a voxel represents a value on a regular grid in three-dimensional space. As with pixels in a 2D bitmap, voxels themselves do not typically have their position explicitly encoded with their values. Instead, rendering systems infer the position of a voxel based upon its position relative to other voxels.

How you will benefit

(I) Insights, and validations about the following topics:

Chapter 1: Voxel

Chapter 2: Texture mapping

Chapter 3: Ray casting

Chapter 4: Scientific visualization

Chapter 5: Volume rendering

Chapter 6: First-person shooter engine

Chapter 7: Volumetric display

Chapter 8: CryEngine

Chapter 9: Software rendering

Chapter 10: Per-pixel lighting

(II) Answering the public top questions about voxel.

(III) Real world examples for the usage of voxel in many fields.

Who this book is for

Professionals, undergraduate and graduate students, enthusiasts, hobbyists, and those who want to go beyond basic knowledge or information for any kind of Voxel.

• Language: English
• Publisher: One Billion Knowledgeable
• Release date: May 13, 2024

Book preview

Chapter 1: Voxel

A voxel represents a value on a regular grid in three-dimensional space in 3D computer graphics. Similar to pixels in a 2D bitmap, voxels normally do not have their position (i.e. coordinates) recorded with their values. Instead, rendering systems determine a voxel's position based on its position relative to other voxels (i.e., its position in the data structure that makes up a single volumetric image).

Unlike pixels and voxels, polygons are frequently represented explicitly by the coordinates of their vertices (as points). As a direct result of this distinction, polygons can effectively represent simple 3D structures with a great deal of empty or homogeneously filled space, but voxels excel at describing regularly sampled spaces that are not homogeneously filled.

In the viewing and interpretation of medical and scientific data (e.g., MRI scans), voxels are frequently employed.

GIS (geographic information systems).

Some volumetric displays characterize their resolution using voxels.

For instance, a cubic volumetric display might be able to show 512×512×512 (or about 134 million) voxels.

Voxel is an image of a three-dimensional space region limited by given sizes, with its own nodal point coordinates in an accepted coordinate system, its own form, its own state parameter indicating its belonging to some modeled object, and the properties of the modeled region, is one of the definitions. This definition provides the following benefit. If a fixed voxel form is utilized throughout the entire model, it is considerably simpler to interact with voxel nodal points, i.e. the point's three coordinates. Nonetheless, there is the simplest type of record: the indexes of the model set's items, often known as integer coordinates. In this instance, model set elements are state parameters, denoting voxels pertaining to the modeled object or its constituent pieces, including their surfaces.

The etymology of the word voxel is similar to that of pixel, with vo indicating volume (instead of image for pixel) and el representing element.; A voxel-described volume may be displayed either through direct volume rendering or through the extraction of polygon iso-surfaces that follow the contours of set threshold values. The marching cubes algorithm is frequently used for isosurface extraction, although there are additional techniques as well.

Voxel data can be processed via ray tracing, ray casting, and rasterisation to generate 2D raster graphics for display on a monitor.

Using raster graphics, one simply raytraces each pixel of the display into the scene while keeping track of an error term to determine when to step. Using a y-buffer, a typical implementation will raytrace each pixel of the display beginning at the bottom of the screen. When a voxel with a higher y value is encountered on the display, it is added to the y-buffer, replacing the old value, and interpolated with the previous y-value to determine the color values. There is a significant disadvantage to voxel rasterization when transformations are used, as this results in severe aliasing. The benefit was the ability to perform rasterization using inexpensive integer calculations on a CPU without hardware acceleration. Carmack mentioned the paucity of graphics cards developed expressly for such rendering, necessitating software rendering as one such issue.

Additionally, Comanche was the first commercial flight simulation to utilize voxel technology. Kyle Freeman created the proprietary Voxel Space engine utilized by NovaLogic.

3D rendering of a µCT scan of a leaf piece, resolution circa 40 µm/voxel when viewed at the full size

A (smoothed) depiction of a macromolecule's voxel data set.

A voxel represents a single sample or data point on a three-dimensional grid with uniform spacing. This data point may contain a single item of data, such as opacity, or multiple pieces of data, such as both opacity and color. The space between voxels is not represented in a voxel-based dataset. Depending on the type of data and the planned application of the dataset, this missing information may be reconstructed and/or approximated, for instance using interpolation.

The value of a voxel may represent various properties. In CT scans, the values are Hounsfield units, giving the opacity of material to X-rays.: 29 Different types of value are acquired from MRI or ultrasound.

In the case of ultrasound scans using B-mode and Doppler data, density and volumetric flow rate are collected as independent channels of data corresponding to the same voxel coordinates.

Despite the fact that voxels provide precision and depth of realism, they are often enormous data sets that are difficult to manage given the bandwidth of conventional processors. However, through efficient compression and manipulation of big data files, consumer market computers may support interactive visualization.

Other data, such a surface normal vector and color, may be beneficial for quick 3D rendering.

Technologies to extend voxels into the fourth and fifth dimensions of data are being researched.

Examples of common voxel applications include volumetric imaging in medicine and landscape modeling in games and simulations. Voxel terrain is utilized rather than a heightmap due of its capacity to portray overhangs, caves, and other 3D terrain characteristics. These concave features cannot be depicted in a heightmap due to the fact that just the top layer of data is recorded, leaving everything below it unrepresented (the volume that would otherwise be the inside of the caves, or the underside of arches or overhangs).

3D Dot Game Heroes features retro-looking voxel visuals.

The Fun Pimps Entertainment produced 7 Days to Die, a voxel-based, open-world survival horror game.

Ace of Spades originally utilized Ken Silverman's Voxlap engine prior to being rewritten with a custom OpenGL engine.

Amok creates its environments using voxels.

The computer game Armored Fist 3 was developed by Novalogic using voxel-based rendering technology.

Blade Runner is a video game whose characters and artifacts were rendered using voxels.

In-development Real-Time-Strategy game Castle Story has topography comprised of smoothed voxels.

NovaLogic's Comanche series of computer games utilizes Voxel Space voxel rasterization for terrain rendering.

Most vehicles in the computer games Command & Conquer: Tiberian Sun, Command & Conquer: Red Alert 2, and Command & Conquer: Yuri's Revenge were rendered using voxels by Westwood Studios.

The landscape systems of Crysis, Cryengine 2, and Cryengine 3 use a combination of heightmaps and voxels.

Action role-playing game Cube World includes procedurally generated voxel landscapes.

Delta Force is a computer game developed by Novalogic using its proprietary Voxel Space rendering engine.

Dual World is a single-shard universe massively multiplayer online role-playing game that employs voxels to construct spaceships, civilizations, and space stations.

Sony Online Entertainment's shelved MMORPGs EverQuest Next and EverQuest Next: Landmark make heavy use of voxels for world development and player-generated content.

Hexplore is a multiplayer role-playing game that employs a voxel engine that enables the user to rotate the isometrically drawn playfield.

Hytale is a voxel-based RPG Sandbox game being developed by Hypixel Studios and funded by Riot Games, with an earliest release date of 2023.

Master of Orion III renders space wars and solar systems using voxel graphics. On PCs without hardware graphic acceleration, 1000-ship battles were rendered sluggishly.

Medieval Engineers is Keen Software House's second voxel-based engineering game inspired by medieval technologies.

Minecraft is a sandbox computer