Computer Graphics Review
Apare_xzc 2020.12.28
Chapter One Introduction
Computer Graphics (CG) for short
- Definition
Computer graphics is the study of how to use computers to represent , process , generate and display graphics.
Simply put, computer graphics is the study of the relevant principles and algorithms that represent graphics in computers and use computers to calculate, process, and display graphics.
Computer graphics is a subject that studies the transformation of graphic representation from parametric method to lattice method. - Related concepts
- Graphics are mainly divided into two categories. One type is geometric figures based on line representation , such as wireframes, engineering drawings, and contour maps. The other type is realistic graphics based on material, texture and lighting representation .
- Graphic representation method
(1) Parameter method . Parametric method is a method of describing graphics with shape parameters and attribute parameters when using geometric methods to establish mathematical models in the design stage .
The shape parameter can be geometric information such as the starting point and ending point coordinates of the line segment. Attribute parameters include non-aggregate parameters such as the color, line type, and width of the line segment. The graphics described by the parameter method are still called graphics.
(2) Lattice method . The dot matrix method is a method of expressing graphics with a pixel matrix with color information in the implementation stage. The described graphics are called images .
Computer graphics is a subject that studies the transformation of graphic representation from parametric method to lattice method.
- Application areas of computer graphics
- The graphical human-computer interaction interface of the Windows operating system is the most direct experience brought by computer graphics.
- Computer graphics is the result of the integration of computer technology, television technology, and graphics and image processing technology.
- Computer graphics has been widely used in the fields of games, movies, science, art, business, advertising, teaching, training and military.
(1) Computer games (click games, online games)
(2) Computer-aided design (Computer Aided Design, CAD) computer aided manufacturing (computer Aided manufacture, CAM) is the earliest applications of computer graphics, as well as the most current computer graphics applications into a tree. The typical representative is AutoCAD system software.
Now the development of buildings, machinery, airplanes, automobiles, ships, and electronic devices almost all use AutoCAD for design.
The other two 3D modeling, animation and rendering softwares published by Autodesk are 3ds max and Maya . The former is mainly used for building modeling and the latter is mainly used for character modeling.
(3) Computer graphics is widely used in art design, called Computer Art (CA) , and animation design is its typical representative. At present, computer animation has been widely used in film and television special effects, commercial advertising, games, computer-assisted teaching and other fields - Morph
- Fractal art
Fractal art is an edge subject that combines fractal geometry and computer graphics.
Fractal realizes complex graphic structure through recursion. Mainly used to describe the natural world that Euclidean geometry cannot describe. Without the help of computer graphics technology, Menger sponge and Sierpinski pads cannot be drawn by hand.
(6) Virtual reality
Virtual reality (virtual reality, VR) technology is a new technology of human-computer interaction that uses computers to generate virtual environments and realistically simulate human visual, auditory, and motion behaviors in a natural environment.
Virtual Reality 3I characteristics : immersion (Immersion) interactivity (Interactivity) imagination (Imagination)
by means of some special equipment, such as data gloves, helmet display, the user can "immerse" into the environment. In virtual reality, what you see is a full-color image, what you hear is a realistic sound, and what you feel is the force of feedback from the virtual environment equipment, resulting in an immersive feeling. Visual simulation is the most important form of virtual reality technology, and it has been widely used in many fields such as urban planning simulation.
(7) Computer Aided Instruction
is a new teaching method that uses computer graphics technology to show abstract principles or invisible processes
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Related disciplines
of computer graphics The disciplines closely related to computer graphics are image processing and pattern recognition .
Computer graphics is researchHow to use the computer to transform the geometric model describing the figure into an image display through a specified algorithmSubject. [3ds max is a famous three-dimensional graphics drawing software].
Image processing is mainlyDifferent processing methods such as enhancement, denoising, restoration, segmentation, reconstruction, encoding, storage, compression and restoration of digital imagesSubject. [Photoshop is a famous image processing software].
Pattern recognition is the subject of extracting features from bitmap images, and then using statistical methods to describe the graphics . [Chinese character handwriting function is a typical application of pattern recognition].
The three disciplines of computer graphics, pattern recognition and image processing promote and develop each other . In recent years, with the widespread use of raster scan displays, the boundaries between these three disciplines have become increasingly blurred. For the problem of aliasing when drawing diagonal lines on a raster scan display in computer graphics, image processing technology can be used for anti-aliasing (or anti-aliasing) processing. For the image input by the scanner, you can use pattern recognition software to recognize it as text, paste it into Word and re-typesetting and editing. These applications show that these three disciplines promote and develop each other. -
The main content and hot technology of computer graphics research
- Computer graphics mainly studies the theory, method and technology of using algorithms and programs to generate images on computers .
- Since the 1980s, one of the research hotspots of computer graphics is to generate highly realistic images . The so-called "have an image as real as a photo".
(1) LOD (levels of detail) technology. If the
object is close to the viewpoint, a higher-detail model is used. If the object is far away from the viewpoint, a lower-detail model is selected. Features: Need to build a 3D model and texture mapping.
(2) IBR (Image Based Rendering) Image-based rendering
IBR technology uses a panorama of the scene to construct a virtual reality system. The advantage of IBR technology is that it completely gets rid of the real-time bottleneck of scene complexity; the disadvantage is that it can only achieve a fixed viewpoint and jump between different scenes, and cannot realize continuous roaming. ● Features: no need for 3D modeling
Chapter 2 MFC Drawing Basics
VC++(6.0) provides software code automatic generation and visual resource editing functions. Microsoft Foundation Class Library (MFC) adopts object-oriented design, encapsulates most of Windows API (Application Program Interface, API) in the form of C++ classes, and contains more than 200 defined base classes. In the process of programming, the design task is generally completed by calling member functions of the base class through MFC.