Diffuse

Enabled

Selects the diffuse behavior for this layer. In Maya or Katana, users can choose to enable or disable the diffuse lobe via a checkbox. Enabled means that all the diffuse parameters are active. Disabled that the values of these parameters will not be included in the result.

RIB: int diffuseBehavior

Default: 1

Color

The diffuse color is the amount of energy reflected back to the viewer in diffuse directions. Typically physically realistic diffuse responses are well below 0.5 and thus require higher-intensity lighting than might be required in old-school CGI setups. The diffuse color is often referred to as albedo in scientific literature.

RIB: color diffuseColor

Default: 0.5 0.5 0.5

Roughness

Controls the diffuse scattering model. Lambertian response is obtained by setting roughness to 0.0. Increasing roughness produces a flatter-look and is implemented via the Oren-Nayar model. This roughness can range from 0.0 to 1.0.

RIB: float diffuseRoughness

Default: 0.0

Sheen

Controls the diffuse retro-reflection effect. This can be used to simulate fuzz, velvet or carpet.

RIB: color sheen

Default: 0.0 0.0 0.0

Incandescence

Controls the incandescence, or glow, of the material.

RIB: color incandescence

Default: 0.0 0.0 0.0

Bump

You can specify a bump map for the exclusive use of the diffuse parameters.

RIB: normal diffuseNn

Default: 0.0 0.0 0.0

Specular

Enabled

Selects the specular behavior for this layer. In Maya or Katana, users can choose to enable or disable the specular lobe via a checkbox. Enabled means that all the specular parameters are active. Disabled means that this layer asserts no opinion about the specular response - none of these parameters are considered.

RIB: int specularBehavior

Default: 1

Color

A coloration for the specular highlights. Usually this should be set to white but we provide it to push toward a non-physical look.

RIB: color specularColor

Default: 1.0 1.0 1.0

Roughness

Controls the sharpness of highlights and reflections. This value can range from 0.01 to 1.0.

RIB: float specularRoughness

Default: 0.05

Refractive Index

Refractive Index is the dielectric index of refraction for the material. Channel values for this parameter typically lie in the range 1 to 3. Since we support 3 color values to capture the spectral effect presets may be prefered over color pickers.

RIB: color specularEta

Default: 1.5 1.5 1.5

Extinction Coefficient

Extinction Coefficient is a second refractive index for the material useful for characterizing metallic behaviors. Channel values for this parameter typically lie in the range 1 - 3. Since we support 3 color values to capture the spectral effect presets may be prefered over color pickers. When 0, the material reacts as a dielectric (glass, clearcoat)> When non-zero, the material responds as a metal would.

RIB: color specularKappa

Default: 0.0 0.0 0.0

Bump

You can achieve some cool effects by controlling the bump for specular independently of the diffuse parameters. If no connection is made here, we use the diffuse bump.

RIB: normal specularNn

Default: 0.0 0.0 0.0

Anisotropy

Controls the shape of the specular highlights and reflections. At 0.0 the shape is circular. Values from -1.0 to 1.0 produce the range of ellipses from fat to tall. The direction of anisotropy can also be controlled by your model texture parameters and by the Shading Tangent parameter. This value can range from -1.0 to 1.0.

RIB: float specularAnisotropy

Default: 0.0

Shading Tangent

Controls the anisotropy direction. Only valid when provided as a texture/connection.

RIB: vector specularTn

Default: 0.0 0.0 0.0

Clear Coat

Enabled

Selects the clearcoat behavior for this layer. In Maya or Katana, users can choose to enable or disable the clear coat lobe via a checkbox. Enabled means that all the clearcoat parameters are active. Disabled means that this layer asserts no opinion about the clearcoat - none of these parameters contribute to this layer.

RIB: int clearcoatBehavior

Default: 0

Color

The clearcoat is a dielectric material, so does not exhibit colored highlights and reflections. The clearcoat color does obscure the underlying material according to the transmission and thickness parameters.

RIB: color clearcoatColor

Default: 1.0 1.0 1.0

Refractive Index

Since clearcoat is a dielectric, we provide a single index of refraction to control the reflection response. Typical values for eta might be in the same range as for glass: 1.5-1.8.

RIB: float clearcoatEta

Default: 1.3

Roughness

Controls the sharpness of the clearcoat highlights and reflections.

RIB: float clearcoatRoughness

Default: 0.01

Thickness

Controls the thickness of the clearcoat, which affects how much the under-materials are affected by the clearcoat color.

RIB: float clearcoatThickness

Default: 0.0

Transmission

Controls the amount and color of light absorpted by the clearcoat. Interoperates with thickness to produce a variety of aging the coating effects.

RIB: color clearcoatTransmission

Default: 1.0 1.0 1.0

Bump

You can achieve some cool effects by controlling the bump for clearcoat independently of the specular and diffuse parameters. Generally a clearcoat is smoother than the underlying materials since it is used to fill in the cracks. Clearcoats can also be scratched or scuffed.

RIB: normal clearcoatNn

Default: 0.0 0.0 0.0

Anisotropy

Usually clearcoats exibit isotropic highlights and reflections. As with specular you can control the the clearcoat's anisotropic behavior through the combination of this parameter (-1.0 or 1.0 is highly anistropic) and Shading Tangent. This value can range from -1.0 to 1.0.

RIB: float clearcoatAnisotropy

Default: 0.0

Shading Tangent

Controls the anisotropy direction. Only valid when provided as a texture/connection.

RIB: vector clearcoatTn

Default: 0.0 0.0 0.0