Introduction to Computer Graphics
Computer Graphics is the branch of computer science that deals with the creation, manipulation, storage, and display of images using computers. It encompasses everything from simple 2D drawings on a screen to complex 3D rendered scenes in films and video games. In the context of modern computing, graphics is no longer a specialized niche—it is a fundamental component of user interfaces, data visualization, scientific simulation, medical imaging, computer-aided design, virtual reality, and entertainment.
History and Evolution
The foundations of computer graphics were laid in the 1950s and 1960s. Ivan Sutherland's Sketchpad (1963) is widely regarded as the first interactive graphics program and introduced the concepts of constraints, object hierarchies, and light-pen interaction. Through the 1970s, raster graphics replaced early vector displays, and companies such as Evans & Sutherland, Silicon Graphics, and later NVIDIA and AMD drove the development of dedicated graphics hardware. Today, the Graphics Processing Unit (GPU) is a massively parallel processor found in virtually every computing device.
Classification of Computer Graphics
Computer graphics is broadly classified into two categories: interactive graphics, where the user can influence the displayed image in real time through input devices, and non-interactive (passive) graphics, where the image is generated without user intervention, as in printed reports. A further classification distinguishes 2D graphics, dealing with images in a plane, from 3D graphics, which simulates the perspective and lighting of a three-dimensional scene projected onto a 2D display.
Applications of Computer Graphics
The applications of computer graphics are pervasive. Graphical User Interfaces (GUIs) allow users to interact with computers through windows, icons, and menus. Computer-Aided Design (CAD) enables engineers and architects to design mechanical parts, electronic circuits, and buildings. Scientific visualization turns complex datasets—from molecular structures to weather patterns—into images that researchers can interpret intuitively. The entertainment industry relies on graphics for animated films, video games, and special effects. Medical imaging techniques such as CT and MRI reconstruct three-dimensional views of the human body from scanned slices. Education and training benefit from flight simulators, anatomy explorers, and interactive textbooks.
Graphics Pipeline Overview
Modern computer graphics systems process images through a pipeline of stages. Geometric models composed of vertices are transformed through modeling, viewing, and projection matrices; primitives such as triangles are assembled and clipped against the viewing volume; each primitive is rasterized into fragments; fragments are shaded using lighting models and textures; finally, fragments are composited into the frame buffer with depth testing and blending. This pipeline is implemented directly in hardware on the GPU, allowing billions of pixels to be processed per second.
Display Technologies
Several display technologies have dominated different eras. The Cathode Ray Tube (CRT) used an electron beam striking a phosphor-coated screen and was the standard for decades. Liquid Crystal Displays (LCDs), Light Emitting Diode (LED) displays, Organic LED (OLED) panels, and plasma screens have largely replaced CRTs. Emerging technologies include micro-LED panels and head-mounted displays for virtual and augmented reality.
Coordinate Systems
Computer graphics relies heavily on coordinate systems. The world coordinate system describes objects in a scene in absolute units. The viewing coordinate system is aligned with the camera's viewpoint. The device coordinate system maps the viewable area onto pixels of a specific display. Transformations between these coordinate systems are performed using matrix multiplication, a topic of central importance in later chapters.
Summary
Computer Graphics combines mathematics, physics, art, and computer science to produce visual representations of data and ideas. Its influence extends from the familiar GUI on every computer to the breathtaking imagery of modern cinema. The chapters that follow develop the mathematical foundations, hardware considerations, and algorithms that make these experiences possible.