3D computer graphics

Three-dimensional (3D) computer graphics
Fundamentals
Modeling Scanning Rendering Printing
Primary uses
3D models Computer-aided design Graphic design Video games Visual effects Visualization Virtual engineering Virtual reality Virtual cinematography
Related topics
Computer-generated imagery (CGI) Animation computer skeletal 3D display Wire-frame model Texture mapping Motion capture Crowd simulation Global illumination Volume rendering
v t e

3D computer graphics, sometimes called CGI, 3-D-CGI or three-dimensional computer graphics, are graphics that use a three-dimensional representation of geometric data (often Cartesian) that is stored in the computer for the purposes of performing calculations and rendering digital images.

3-D computer graphics, despite to what the name suggests, are most often displayed on two-dimensional displays. such as 3D films and similar techniques are 2D but with the help of visual depth and effects it can give the appearance of 3 dimensional objects.

3D graphics and 2D graphics typically use completely different methods and formats for creation and rendering. However, 3D graphics uses some aspects of 2D graphics to help render objects and techniques and vice versa. 3-D computer graphics also rely on many of the same algorithms as 2-D computer vector graphics.

Objects in 3-D computer graphics are often referred to as 3-D models. A 3-D model is a mathematical representation of any three-dimensional object; a model is not technically a graphic until it is displayed. A model can be displayed visually as a two-dimensional image through a process called 3-D rendering, or it can be used in non-graphical computer simulations and calculations. 3D printing is another element of 3D graphics, that creates a physical representation of themselves, with some limitations.

History

In 1960 Ivan Sutherland introduces a sketchpad as the first graphic design interfaces. During this time frame 3D modeling was very restricted as it was a highly complex and expensive. In 1961 the Sketchpad launch and ran on TX-1 a computer at MIT.

In 1968 Sutherland opened the first ever department of computer technologies at the University of Utah with his partner David Evans, where they recruited hundreds of students to develop the sketch pad and 3D modeling further.

Eventually in 1968 they were able to open the first 3D graphics company to be founded. Evan and Sutherland's achievements paved the way for more people to get into the 3D graphic industry. One such pioneer is Ed Catmull who in addition to numerous technical advances in graphics, decades later would go on to found Pixar.

At the Link Flight Simulation Division^[1] which created the Link Simulator part of the Singer Company, technologists in the late 1970s through the 1980s notably Roy Latham who later published the "Dictionary of Computer Graphics" and worked on high performance image generation, Johnson Yan who wrote and patented extensively on digital image generation, and texturing approaches,^[2] and Nicholas Szabo another early pioneer in visual systems for flight simulation as well as several others from Link devised a number of computer generated imagery (CGI) and practical 3D graphics applications still used today.

By the 1970s, a lot more new companies were created and established to better the design software for user needs. And with a lot more competition ADAM (Automated Drafting and Machine) was created. ADAM was a software that could be used on multiple systems at the same time. In the 1980s 3D modeling software was a big want for consumers.

In 1981 IBM (International Business Machines) launched their first personal computer. This led to a widespread of CAD usage in business operations in aerospace, automotives, etc.

In 1983 AutoCAD was launch, AutoCAD was more of a 2D designing software, but it was important for the growth and development for 3D software.

The 1990s was the peak for CAD software, it became standard practice for industries designing products. CAD prices eventually dropped allowing access for freelancers, smaller companies, and even hobbyists had access. 3D modeling was so popular among all user (intermediate to beginner) It eventually it became part of universities' curriculum allowing it became something you can get taught and certified for.

Towards the end of the 1990s, software companies created a new evolution to 3D modeling called 3D printing.

Overview

3-D computer graphics production workflow falls into three basic phases:

1. 3-D modeling – the process of forming a computer model of an object's shape
2. Layout and CGI animation – the placement and movement of objects (models, lights etc.) within a scene
3. 3-D rendering – the computer calculations that, based on light placement, surface types, and other qualities, generate (rasterize the scene into) an image

Modeling

The first phase is '3D modeling,' which is the process of forming the shape of an object. Models can be a real-life object scanned into a computer with special tools, or models can be created with a simulation within a computer software. Some popular software used for 3D modeling is the Polygonal Modeling, the Patch Modeling and the NURBS Modeling. With 3D modeling it uses a series of polygon shapes to structure the model. A polygon is a flat geometric figure with at least 4 angles, that 3D artist uses to form or to build a detailed 3D model and or objects.

Layout and animation

The second phase is the 'Layout and Animation,' which is the placement and movement of objects within a scene. Before rendering into an image, objects must be laid out in a 3D scene. This defines the spatial relationships between the object, the location and size. Animation refers to the temporal description of an object (i.e., how it moves and deforms over time). Some popular methods being Keyframing, inverse kinematics, and motion-capture. These methods and techniques are used in a combination to create movement within the screen.

Materials and textures

Materials and textures are properties that the render engine uses to render the model. One can give the model materials to tell the render engine how to treat light when it hits the surface. Textures are used to give the material color using a color or albedo map, or give the surface features using a bump map or normal map. It can be also used to deform the model itself using a displacement map.

Rendering

And lastly the third phase is 3D rendering. Rendering converts a model into an image either by simulating light transport to get photo-realistic images, or by applying an art style as in non-photorealistic rendering. The two basic operations in realistic rendering are transport (how much light gets from one place to another) and scattering (how surfaces interact with light).

This step is usually performed using 3-D computer graphics software or a 3-D graphics API. Altering the scene into a suitable form for rendering also involves 3-D projection, which displays a three-dimensional image in two dimensions. Although 3-D modeling and CAD software may perform 3-D rendering as well (e.g., Autodesk 3ds Max or Blender), exclusive 3-D rendering software also exists (e.g., OTOY's Octane Rendering Engine, Maxon's Redshift).   

• Examples of 3-D rendering
• 
  A 3-D rendering with ray tracing and ambient occlusion using Blender and YafaRay
• 
  A 3-D model of a Dunkerque-class battleship rendered with flat shading
• 
  During the 3-D rendering step, the number of reflections "light rays" can take, as well as various other attributes, can be tailored to achieve a desired visual effect. Rendered with Cobalt.
• 
  A 3-D rendering of a penthouse

Software

3-D computer graphics software produces computer-generated imagery (CGI) through 3-D modeling and 3-D rendering or produces 3-D models for analytic, scientific and industrial purposes.

File formats

There are many varieties of files supporting 3-D graphics, for example, Wavefront .obj files and .x DirectX files. Each file type generally tends to have its own unique data structure.

Each file format can be accessed through their respective applications, such as DirectX files, and Quake. Alternatively, files can be accessed through third-party standalone programs, or via manual decompilation.

Modeling

3-D modeling software is a class of 3-D computer graphics software used to produce 3-D models. Individual programs of this class are called modeling applications or modelers.

3-D modeling starts by describing 3 display models : Drawing Points, Drawing Lines and Drawing triangles and other Polygonal patches.^[3]

3-D modelers allow users to create and alter models via their 3-D mesh. Users can add, subtract, stretch and otherwise change the mesh to their desire. Models can be viewed from a variety of angles, usually simultaneously. Models can be rotated and the view can be zoomed in and out.

3-D modelers can export their models to files, which can then be imported into other applications as long as the metadata are compatible. Many modelers allow importers and exporters to be plugged-in, so they can read and write data in the native formats of other applications.

Most 3-D modelers contain a number of related features, such as ray tracers and other rendering alternatives and texture mapping facilities. Some also contain features that support or allow animation of models. Some may be able to generate full-motion video of a series of rendered scenes (i.e. animation).

Computer-aided design (CAD)

Computer aided design software may employ the same fundamental 3-D modeling techniques that 3-D modeling software use but their goal differs. They are used in computer-aided engineering, computer-aided manufacturing, Finite element analysis, product lifecycle management, 3D printing and computer-aided architectural design.

Complementary tools

After producing video, studios then edit or composite the video using programs such as Adobe Premiere Pro or Final Cut Pro at the mid-level, or Autodesk Combustion, Digital Fusion, Shake at the high-end. Match moving software is commonly used to match live video with computer-generated video, keeping the two in sync as the camera moves.

Use of real-time computer graphics engines to create a cinematic production is called machinima.^[4]

Other types of 3D appearance

Photorealistic 2D graphics

Not all computer graphics that appear 3D are based on a wireframe model. 2D computer graphics with 3D photorealistic effects are often achieved without wireframe modeling and are sometimes indistinguishable in the final form. Some graphic art software includes filters that can be applied to 2D vector graphics or 2D raster graphics on transparent layers. Visual artists may also copy or visualize 3D effects and manually render photorealistic effects without the use of filters.

2.5D

Some video games use 2.5D graphics, involving restricted projections of three-dimensional environments, such as isometric graphics or virtual cameras with fixed angles, either as a way to improve performance of the game engine or for stylistic and gameplay concerns. By contrast, games using 3D computer graphics without such restrictions are said^{[by whom?]} to use true 3D.

See also

References

Miyatovich, K. M. am K. (2023, April 24). What are polygons in 3D modeling (the ins and outs). The Motion Tree. https://themotiontree.com/what-are-polygons-in-3d-modeling/

Kramer, L. (2018). A look inside 3D design: What goes into it and where it's headedL. 99designs by vista. https://99designs.com/blog/design-history-movements/3d-design/

Ekaran, S. (2021, May 30). When did 3D modeling start? A brief history. SelfCAD. https://www.selfcad.com/blog/when-did-3d-modeling-start-a-brief-history

3D Horse. (2017, August 14). History of 3D Computer Graphics. 3D Horse. https://www.3dhorse.com/blogs/3d/history-of-3d-computer-graphics#:~:text=1%20%201960s%20Computer%20graphics%20design%20was%20an,Early%202000s%20...%206%20%202005%20to%20date

External links

Wikimedia Commons has media related to 3D computer graphics.

Look up computer graphics in Wiktionary, the free dictionary.

• A Critical History of Computer Graphics and Animation (Wayback Machine copy)
• How Stuff Works - 3D Graphics
• History of Computer Graphics series of articles (Wayback Machine copy)
• How 3D Works - Explains 3D modeling for an illuminated manuscript