The Specular layer is used for shiny materials like plastics, or clear materials like glass. Refer to the Glossy, Specular, and Universal Material topics in this manual for more information.

Figure 1: Specular layer Node

Parameters

    • Compatibility version - The Octane version that the behavior of this node should match.
    • Enabled - Whether this layer is applied or skipped.
    • Specular - The layer's coating color.
    • Transmission - The layer's transmission color.
    • BRDF Model - The BRDF (Bidirectional Reflectance Distribution Function) determines the amount of light that a material reflects when light falls on it. For Glossy materials, you can choose from multiple BRDF models. Specific geometric properties (the micro-facet distribution) of the surface affects each BRDF, which describes the surface's microscopic shape (i.e. micro-facet normals) and scales the brightness of the BRDF's reflections. Refer to the topic on BRDF Models for more information.
      • Octane
      • Beckmann
      • ĢGX
      • GGX (energy preserving)
      • STD
    • Roughness - The layer's roughness.
    • Affect Roughness - The percentage of roughness affecting subsequent layers' roughness.
    • Anisotropy - The layer's anisotropy. A value of -1 is horizontal, while 1 is vertical. A value of 0 is Isotropic.
    • Rotation - The rotation of the specular anisotropic reflection.
    • Spread - Determines the tail spread of the specular BSDF.
    • IOR - The specular reflection's or transmission's Index Of Refraction.
    • 1/IOR Map - The Index of Refraction map. Each texel represents 1/IOR. When this is empty, OctaneRender® uses the IOR value. If this is not empty, then this parameter overrides the Index Of Refraction set by the IOR value.
    • Allow Caustics - If enabled, the photon tracing kernel will create caustics for light reflecting or transmitting through the object.
    • Film width (um) - Simulates the look of a thin film of material on the surface. This is useful when you want to create an effect such as the rainbow colors that appear on an oil slick surface. Larger values increase the effect's strength.
    • Film IOR - Controls the thin film's IOR by adjusting its visible colors.
    • Thin Layer - Makes the layer very thin so it reflects, or goes straight though the layer.
    • Bump - Creates fine details on the material’s surface using a Procedural or Image texture. Often a Greyscale image texture connects to this parameter - light areas of the texture indicate protruding bumps, and dark areas indicate indentation. You can adjust the Bump map's strength by adjusting the Power or Gamma values on the Image texture node.
    • Bump height - The height represented by a normalized value of 1.0 in the bump texture. 0 disables bump mapping, negative values will invert the bump map.
    • Normal - Distorts layer normals using an RGB image.
    • Dispersion Coefficient - This is the B parameter of the Cauchy dispersion model. Increasing this value increases the coloration amount and dispersion in the layer’s transmission and caustics.
    • Dispersion mode -  Select how the IOR and dispersion coefficient inputs are interpreted
      • Abbe number
      • Cauchy formula
    • Layer Opacity - Controls the layer's opacity with a Greyscale texture.