Renderers

Renderers are software or hardware components that convert a description of a scene into a visual image. They are central to computer graphics, film and television production, video games, and web browsers, and they can operate in real time or as offline renderers. Real-time renderers aim for interactive frame rates, trading some accuracy for speed, while offline renderers prioritize image quality and physical realism, often using multi-sample, Monte Carlo methods.

In 3D graphics, a renderer takes inputs such as geometry, materials, lights, cameras, and textures, and produces a 2D image. Rendering pipelines typically include steps for visibility, shading, texturing, and illumination. Two broad approaches are rasterization, which projects geometry onto the screen and evaluates shading per fragment, and ray tracing, which simulates light paths by shooting rays from the camera or from light sources. Many modern renderers combine both, using rasterization for primary visibility and ray tracing for reflections, shadows, and global illumination. Physically based rendering models describe material responses to light in a consistent way, enabling more realistic results. Additional passes or post-processing, like anti-aliasing, tone mapping, and denoising, refine the final image.

Renderers are used across domains: game engines and interactive applications rely on real-time renderers optimized for hardware acceleration; offline renderers are used in film, architectural visualization, and product design to achieve higher fidelity. In browsers, the rendering pipeline also encompasses 2D layout, paint, and compositing stages to display HTML and CSS, sometimes leveraging GPU acceleration for performance.