The Disney Principled material is based on an implementation of the Disney Principled shader introduced in 2012 by Walt Disney Animation Studio. It offers an artist-friendly set of parameters to describe many different types of materials. The material is kept to ease the port of existing lookdev.
It is fully superseded by the Autodesk Standard Surface which offers much more controls.
The base attribute set controls the base physical properties of the material such as its color, roughness etc...
The Base Color attribute simply defines the surface color, whether the material is dielectric or metallic.
The Roughness attribute controls the roughness of the material affecting diffuse, specular and transmission.
The Metallic attribute controls how much the material reacts as a conductive material. This can be seen as defining the concentration of metal in the dielectric material. When set to 0% the material reacts as would a pure dielectric whereas at 100% it reacts like a pure conductor. The metallic model has no diffuse component and also has a tinted incident specular, equal to the base color.
To create more realistic metals and set the incident specular color, please refer to the Metallic Edge Color attribute, under the Reflection Advanced group of attributes.
The Specular attribute controls the incident specular amount. Note that there is no explicit index-of-refraction (IOR) on the Disney Principled material. Instead the IOR directly depends on the Specular value where: 0% corresponds to and IOR of 1.0, 50% to 1.5 and 100% 1.8.
The Specular Tint attribute Tints the incident specular towards the base color. Grazing specular is still achromatic.
The Specular Color attribute defines the specular color.
Metallic Edge Color#
The Metallic Edge Color attribute defines the color bias as the viewing direction becomes parallel to the surface. This is particularly useful in order to create realistic metals. Below are some real-world values for different metals:
The Anisotropic attribute controls the aspect ratio of the specular highlight (0 = isotropic surface, 100% = max anisotropy).
The Anisotropic Rotation attribute rotates the direction of anisotropy, with 1.0 going full circle.
The Clear Coat attribute is a second, special-purpose specular lobe mainly used to simulate a layer of clear coat on top of materials.
Clear Coat Glossiness#
The Clear Coat Glossiness attribute controls the clear coat's appearance, 0% yielding a satin aspect and 100% yielding a glossy aspect.
The Subsurface attribute controls how light penetrates and scatters under the surface simulating translucent materials. When the value is set to 0% no subsurface scattering is evaluated. At 100% the material is considered fully translucent. In between values are a blend between a Lambertian diffuse and a BSSRDF model.
|Subsurface Color||Define the color that is reflected from the surface after the light has traveled and bounced back from inside.|
|Subsurface Radius||Set the maximum distance lights can travel inside the material. The higher the value, the more translucent the material becomes.|
|Subsurface Group||Specify the name of the group among which illumination propagates between SSS materials sharing the same name.|
The Disney Principled material extends the original shader by supporting transmission blending with the diffuse layer.
The Transmission Tint attribute sets the amount to tint the transmission towards Base Color. In the following example, the Base Color attribute was set to orange and as the Transmission Tint is increased, the Base Color comes through.
The Transmission Color attribute multiply the transmission color by the specified color.
The Sheen attribute add an additional grazing component which is primarily intended for cloth.
The Sheen Tint attribute controls the amount to tint sheen towards base color.
The Sheen Color attribute defines the sheen color.
Emission is controlled by the Weight and Color