How do computer graphics create images for screens and other media?

Computer graphics create images by transforming mathematical models into visual displays through a combination of specialized hardware and software algorithms. The process generally involves several key stages:12

Modeling and Rendering

Computers represent objects using three-dimensional data, often constructed from polygons, Bezier curves, or B-splines. To display these on a screen, the system performs rendering, which involves calculating how these objects appear from a specific viewpoint. This includes "hidden surface elimination" to ensure that front-facing objects correctly obscure those behind them.12

Image Display

Modern systems primarily use raster graphics, where images are stored as bitmaps and displayed on a screen composed of a grid of pixels. The quality and detail of these images depend on the display resolution, which defines the number of pixels across and high.13

Shading and Realism

To achieve realistic appearances, systems apply shading techniques—such as Gouraud or Phong shading—to model surface textures and light interactions. Advanced methods like ray tracing use optical laws of reflection and refraction to simulate complex lighting, while radiosity techniques model light as energy to account for diffuse reflections.1

Hardware Acceleration

The graphics processing unit (GPU) is essential for this process, as it performs the intensive mathematical calculations required to render images in "real time," taking the load off the central processor. Modern systems may also use machine learning, such as Deep Learning Super Sampling, to reconstruct high-resolution images from lower-resolution data, further enhancing efficiency.41