Physically Based Rendering (PBR) is an approach to 3D computer graphics rendering that simulates how light interacts with surfaces according to real-world physical principles, producing results that more accurately replicate the appearance of actual materials under different lighting conditions. Rather than using simplified shading models that approximate surface appearance, PBR calculates how light is absorbed, reflected, and scattered based on material properties that correspond to measurable physical quantities.

PBR workflows describe materials using properties like albedo (base color), metalness (whether a surface behaves like metal or non-metal), roughness (how polished or matte a surface is), and normal maps (surface microdetail that affects how light hits the surface). These parameters, combined with physically accurate lighting models, allow artists to create materials that respond correctly to any lighting environment - a rough metal surface in bright sunlight looks like rough metal, in dim candlelight it still reads as rough metal, because the underlying material properties remain physically consistent across different illumination. PBR has become the standard approach in real-time 3D rendering for games and is widely used in film VFX pipelines, product visualization, and architectural rendering.

Understanding PBR is relevant for creators who combine AI-generated content with 3D rendered assets or use AI tools to generate textures and materials for 3D workflows. The visual characteristics of PBR materials - physically plausible reflections, consistent material behavior across lighting, spatially coherent shadows - can also inform how to prompt AI video generators when seeking realistic material qualities in generated footage.