Physically Based Rendering (PBR) seeks to render images in a way that models the flow of light in the real world. Blender's Cycles rendering engine is a PBR engine. The material system associated with Cycles is part of a PBR pipeline. Use this tag for questions pertaining to the PBR aspects of Blender's rendering pipeline.
Wikipedia describes Physically Based Rendering (PBR) as an
approach that seeks to render images in a way that models the flow of light in the real world.
Blender's Cycles rendering engine is
Blender’s physically-based path tracer for production rendering.
Cycles uses a node-based material system. Prior to the introduction of the Principled BSDF materials relied on a complex setup using Fresnel and other nodes to provide physics based materials for Cycles to render. For some complex materials, or for artistic control, such setups are still in use.
Use this tag for questions pertaining to the PBR aspects of Blender's rendering pipeline.
