1. What is Computer Graphics?

Definition: Computer Graphics (CG) is the field of computing that deals with generating, manipulating, and representing visual images using computers. It includes both 2D and 3D graphics, visualization, animation, and interactive graphics for applications like design, gaming, simulations, and HCI.

2. Early Developments (1950s–1960s)

1. 1950s: Beginnings of graphical output

   • Computers were primarily used for calculations; output was text-based.
   • Early experiments with plotting devices and oscilloscopes allowed simple line drawings.
   • Example: SAGE system (Semi-Automatic Ground Environment) used CRT displays for radar visualization.

2. 1960s: Interactive graphics

   • Ivan Sutherland created Sketchpad (1963), the first interactive computer graphics system.

   • Sketchpad introduced:

     • Graphical user interfaces (GUI) concepts
     • Object-oriented manipulation of graphics
     • Light-pen interaction

Significance: Marked the beginning of interactive graphics and CAD (Computer-Aided Design).

3. Development of Graphics Hardware (1970s)

• Introduction of raster graphics displays replacing vector displays
• Growth of frame buffers for storing images in memory
• Emergence of basic 3D graphics algorithms for rendering, transformations, and clipping
• Early graphics programming languages like GRAFIX and FORTRAN Graphics Libraries

Applications: Scientific visualization, military simulations, and early video games.

4. 3D Graphics and Modeling (1980s)

• Development of 3D graphics algorithms:

  • Hidden surface removal
  • Shading models (Gouraud, Phong)
  • Polygonal modeling

• Introduction of high-level graphics APIs:

  • PHIGS (Programmer’s Hierarchical Interactive Graphics System)
  • Early OpenGL prototypes

• Growth of CAD/CAM systems in engineering, architecture, and industrial design

• Animation became possible through frame-by-frame rendering

5. Advanced Computer Graphics (1990s)

• Emergence of realistic 3D graphics:

  • Texture mapping, lighting, shadows, anti-aliasing
  • Particle systems for natural phenomena (fire, smoke, water)

• Development of Graphics Workstations (Silicon Graphics Inc.)

• Rise of video games and CGI in movies

• Introduction of early virtual reality (VR) systems and HCI-based interaction models

Applications: Movies (Jurassic Park), video games, virtual simulations, medical imaging.

6. Modern Computer Graphics (2000s–Present)

• GPU revolution: Graphics Processing Units allow real-time rendering of complex 3D scenes

• APIs and frameworks: OpenGL, DirectX, Vulkan, WebGL

• Realistic rendering techniques:

  • Ray tracing
  • Global illumination
  • Physically based rendering (PBR)

• Interactive graphics & HCI integration:

  • Touch screens, VR, AR, and mixed reality interfaces
  • User-centered design for graphics applications

• Applications:

  • Gaming and entertainment
  • Scientific visualization
  • Virtual reality and augmented reality
  • Medical imaging and simulations

7. Key Milestones in Computer Graphics History

Key Takeaways

• Computer Graphics evolved from simple line drawings to highly realistic, interactive, and immersive visual systems.
• Major developments include interactive graphics, 3D modeling, realistic rendering, and GPU-based acceleration.
• Integration with HCI has enabled user-friendly interfaces, VR/AR applications, and real-time visualization.
• Modern CG is foundational in entertainment, design, simulation, and scientific visualization.