Three-dimensional graphics are graphics that use a 3-dimensional representation of geometric shapes (often Cartesian) stored in a computer for the purposes of calculating and rendering two-dimensional images. Such pictures can be saved for later viewing or displayed in real time.
What it is?
Three-dimensional computer graphics are based on many of the same algorithms as two-dimensional computer vector in the wireframe model, and two-dimensional computer raster in the final displayed image. In computer graphics applications, 2D programs can use 3D methods to produce similar effects (for example, lighting), and 3D can use 2D rendering methods.
Three-dimensional graphics are often called 3D models. In addition to the rendered image, the model is contained in a graphic data file. However, there are differences: a three-dimensional model is a mathematical representation of a three-dimensional object. It is technically not a graphic until it is displayed. It can be displayed visually as a two-dimensional image through a process called 3D rendering, or used in non-graphic computer simulations and calculations.
In 3D printing, these models are likewise converted to a three-dimensional physical representation with restrictions on how accurate rendering can be for a virtual model.
History of technology
The three-dimensional graphics system has a rather long history. William Fetter has been credited with the term “computer graphics” since 1961 to describe his work at Boeing. One of the first works in the style of computer animation was Futureworld (1976), which included the animation of a human face and hand. This technology originally appeared in the 1972 A Computer Animated Hand experimental short film, created by University of Utah students Edwin Catmull and Fred Park. From that moment, three-dimensional graphics - this is a breakthrough technology, which began to develop very actively to the present.
3D graphics software began to appear for home computers in the late 1970s. The earliest known example is 3D Art Graphics, a set of three-dimensional computer graphic effects written by Kazumasa Mitazawa and released in June 1978 for Apple II.
How it's done?
Creating three-dimensional graphics is divided into three main stages:
- 3D modeling - is the process of creating a computer model that displays the shape of an object.
- Layout and animation - placing and moving objects inside the scene.
- 3D rendering - computer calculations that generate an image based on the location of light, surface types and other qualities.
Modeling
Modeling describes the process of creating the shape of an object. The two most common sources of 3D models are as follows:
- those that an artist or engineer creates on a computer using any 3D modeling tool;
- models scanned into a computer from real objects.
They can also be made procedurally or using physical modeling. In fact, a three-dimensional model is created from points called vertices that define the shape and form the polygons. To do this, use the construction of three-dimensional graphs.
A polygon is a region formed by at least three vertices (a triangle). In turn, a polygon of n-points is an n-gon. The integrity of the model in general and its suitability for animation depend on its structure. For it to be functional, you need to correctly build a three-dimensional graph.
Modeling process
There are three common methods for representing a model. They differ like this:
- Polygonal - points in three-dimensional space, called vertices, are connected by segments, forming a polygonal grid. Most modern 3D models are built as textured polygonal because they are flexible and computers can display them very quickly. However, polygons are flat and can only approach curved surfaces using many polygons.
- Curve modeling - surfaces are defined by curves that are affected by weighted control points. The curve follows (but does not necessarily interpolate) the points. Increasing the weight for the point will draw the curve closer to it. Curve types include heterogeneous rational B-spline (NURBS), patches, splines, and geometric primitives.
- Digital is still a relatively new modeling method. It has become very popular over the past few years.
Today, there are three types of digital modeling:
- The offset that is most commonly used in applications. At this point, a dense model is applied (often generated by the subdivision surfaces of the polygonal control grid), which stores new locations for vertex positions using an image map that stores adjusted locations.
- Volumetric, weakly based on voxels, which has similar displacement capabilities, but does not suffer from boundary stretching, when there are not enough points to achieve object deformation.
- Dynamic tessellation is similar to voxels, but it divides the surface by triangulation to maintain a smooth surface and to obtain finer details.
Modeling can be performed using a special program (for example, Cinema 4D, 3ds Max, Maya, Blender, Modo, LightWave) or an application component (Shaper, Lofter in 3ds Max), or using some scene description language (like in POV-Ray) . Sometimes there is no strict difference between these phases. In these cases, 3D modeling is only part of the scene creation process.
Complex materials, such as moving sand, clouds, and liquid sprays, are modeled using particle systems and represent a mass of three-dimensional coordinates that are assigned points, polygons, textures, or spirals.
Materials and textures
Materials and textures are properties that the rendering engine uses to create the model. In an unbiased rendering mechanism, such as blender cycles, you can give an indication of the engine based on model materials. For example, you can configure how to process light when it hits the surface.
Textures are used to color a material using a color map or albedo, or add surface features using a map of bumps or normals. It can also be used to modify the model itself in shape using a displacement map. Despite the fact that it is created through the construction of three-dimensional graphs, these processes have a strong influence.
Layout and animation
Before rendering to the image, objects must be placed in the composition. This determines the spatial relationships between different objects, including their size and location. Animation is a temporary description of an object (that is, how it moves and deforms in time). Common methods include cropping, inverse kinematics, and motion capture. These methods are often used in combination, and have a direct impact on the performance of 3D graphics. As with animations, physical modeling also defines motion.
What is rendering?
Rendering turns a model into an image by simulating light transfer to obtain photorealistic images or by applying an artistic style, as in non-photorealistic rendering.
In realistic rendering, the two main operations are transfer (how much light gets from one place to another) and scattering (the interaction of surfaces with light).
Typically, this step is performed using 3D computer graphics software or an API for it. Changing the scene to a suitable form for rendering also includes a three-dimensional projection that displays a 3-dimensional image in two dimensions. Although 3D modeling software and CAD can also do 3D rendering (such as Autodesk 3DS Max or Blender), there is also exclusive 3D rendering software.
Software
3D graphics programs create computer-generated images (CGI) using 3D modeling and rendering. Or create models for analytical, scientific and industrial purposes.
3D modeling applications are a class of software for computer three-dimensional graphics used to create three-dimensional models. Individual programs of this class are called modeling services or model developers.
Such services allow users to implement and modify models using a 3D mesh. So artists can subtract, add, stretch and otherwise modify the grid as they wish. Models can be viewed from different angles, usually simultaneously. They can be rotated, and the view - increase and decrease.
Most 3D programs include a number of related options, such as ray tracers and other rendering alternatives and texture makers. Some also offer features that support or enable animation of models. A number of them may be able to generate full-motion video from a series of rendered scenes (i.e. animations).
CAD systems
Three-dimensional graphics are the result of the interaction of various services. Computer aided design software can use the same fundamental methods as the software for the simulation itself, but their purpose is different. They are used in computer design, automated production, finite element analysis, product lifecycle management, 3D printing and computer-aided architectural design.
Additional tools
After production, the video studios are then edited or combined using a program such as Adobe Premiere Pro or Final Cut Pro at a medium level, or Autodesk Combustion, Digital Fusion or Shake at a high level. Moving image matching software is commonly used for real-time editing with computer-generated video and synchronizes them as the camera moves.
Communities
There are many websites for software developers, but there are also some amateur resources. These communities allow members to seek advice, post tutorials, provide product reviews, or publish examples of their own work.
Differences from other types of computer graphics
Not all computer graphics that appear in 3D are based on a wireframe model. Its two-dimensional variety with three-dimensional photorealistic effects is often achieved without wireframing and is sometimes indistinguishable in its final form. Some graphics programs include filters that can be applied to two-dimensional vector or two-dimensional raster graphics on transparent layers. Visual artists can also copy or visualize 3D images and manually create photorealistic effects without using filters.
However, this mode of three-dimensional graphics in video and animation often requires special equipment (glasses) for better viewing.
Pseudo-3D and Real 3D
Some video games use limited projections of three-dimensional environments, such as isometric graphics or virtual cameras with fixed angles, designed to improve the performance of the game engine or for stylistic and game tasks. It is believed that such games use pseudo-3D graphics.
The performance of three-dimensional graphics and games created by modeling is significantly different.