15 Metals with Rust and Physically-Based Fresnel + Surface Imperfections | PBR Blender Shader Collection

0 ratings

Get high-quality metal surfaces in Blender with this physically-based metal shader collection. It has physically-based Fresnel curves, rust/tarnish/corrosion/oxidation, and surface imperfections/grunge.

Physically-Based Fresnel Curves

Blender’s built-in Fresnel node and its Principled BSDF shader provide an approximation of Fresnel reflectance that is the same for all wavelengths. In real life, objects’ Fresnel reflectance differs depending on the wavelength and the polarization of the incoming light.

While light polarization and spectral rendering are not supported in Blender, custom R/G/B Fresnel curves can be manually implemented to more closely reflect reality. And these shaders have that all done for you: each of the metal materials has 3 different Fresnel reflectance curves—a Fresnel curve for the red primary (630 nm wavelength), a Fresnel curve for the green primary (532 nm wavelength), and a curve for the blue primary (467 nm wavelength).

Modeling separate Fresnel curves for R, G, and B is the most physically accurate representation of metals’ reflectance behavior you can get without using spectral rendering.

5 Surface Imperfection/Grunge Textures Included

The download comes with a ZIP file of 5 surface imperfection/grunge textures (which were used in the renders on this page). These textures can help make your metal materials look very realistic.