PBR (Physically Based Rendering)

PBR (Physically Based Rendering / Physically Based Rendering) is a technical term that is extremely important in rendering and optimizing game graphics (technical art). A state-of-the-art drawing method that uses mathematical formulas to model physical laws such as absorption and reflection of light and the roughness of materials, and reproduces realistic and consistent textures under any lighting environment.

Real-world analogy: Physical rules that make a ``real leather jacket'' or ``real iron plate'' look real under any lighting

PBR is a physics rule that makes real-world materials (steel, wood, plastic) always look real, whether in the sun, under the neon lights of a club, or by candlelight.'' In the old days (non-PBR), artists would draw with a fixed color, saying, ``This metal always shines in a gold color.'' PBR only sets the essence of the substance: ``This substance is iron and has a 80% smoothness.'' The GPU then automatically performs an ultra-realistic physical simulation that says, ``Because the current ambient light is like this, the reflection will be this strong,'' so the perfect texture is maintained no matter where you place it.

Detailed mechanism and operating principle

Use URP's "Lit Shader" and Shader Graph's "Lit" master node to create "Albedo (basic color)", "Metallic (Metallicity)", "Smoothness.