The Specular BSDF combines multiple layers into a single easy to use node.
It is similar to the Principled BSDF node but uses the specular workflow instead of the metallic. It has far fewer parameters and supports less features. Both might be merged into one node in the future.
The specular workflow functions by specifying the facing (along normal) reflection color. The result may not be physically plausible because there is no energy conservation.
- Base Color
Diffuse surface color. For conductor materials (metals) it should be black.
Amount of specular reflection. Specifies facing (along normal) reflectivity. Conductor materials (metals) can have colored specular reflection.
To compute this value for a realistic material with a known index of refraction, you may use this special case of the Fresnel formula: \(specular = ((ior - 1)/(ior + 1))^2\)
water: ior = 1.33, specular = 0.02
glass: ior = 1.5, specular = 0.04
diamond: ior = 2.417, specular = 0.17
Specifies microfacet roughness of the surface for diffuse and specular reflection.
When converting from the older Glossy BSDF node, use the square root of the original value.
- Emissive Color
Color of the emitted light. This light is added to the BSDF result.
Transparency factor. This is the inverse of the alpha channel (1 - alpha) you find in an image. Use an Invert node to convert alpha to transparency. This will only have an effect if the material uses a blend mode other than opaque.
Controls the normals of the base layers.
- Clear Coat
Extra white specular layer on top of others. This is useful for materials like car paint and the like.
- Clear Coat Roughness:
Roughness of clear coat specular.
- Clear Coat Normal
Controls the normals of the Clear Coat layer.
- Ambient Occlusion
Amount of occlusion to apply to indirect lighting. Usually a bake ambient occlusion map. The final occlusion factor is the minimum of this input and the runtime ambient occlusion effect.
Standard shader output.