How do artists use computer graphics to create animations and special effects?

Artists and technicians use computer graphics to create animations and special effects by leveraging mathematical modeling, rendering algorithms, and digital compositing to simulate complex visual phenomena.

Computer Animation

In computer animation, artists translate three-dimensional figures into digital terms. Once digitized, computers can generate sequences of images that simulate movement or rotation through space. This process can involve:12
* Computer-assisted animation: Using software to facilitate stages of production, such as automating camera movements or generating "in-between" frames.12
* Computer-generated animation: Creating imagery directly through mathematical or computer language rather than traditional drawing or photography.2

Special Effects and Rendering

Modern special effects rely heavily on computer-generated imagery (CGI) to produce elaborate and realistic visuals. Techniques include:3
* 3-D Rendering: Artists use polygons and curves (such as Bezier curves) to model objects. Algorithms handle "hidden surface elimination" to ensure objects correctly obscure one another based on the viewer's perspective.4
* Shading and Texturing: To achieve realism, artists apply techniques like Phong shading to calculate light interaction per pixel. Advanced methods like ray tracing use optical laws of reflection and refraction, while radiosity models light as energy to simulate indirect illumination.4
* Compositing: Computers replace laborious laboratory processes for creating mattes. Digital tools allow for the seamless combination of live-action footage with computer-generated elements, often replacing traditional blue-screen or optical printing methods.35

These processes are computationally intensive, often requiring parallel processing or "farms" of computers to render complex scenes.4