BSDF Principista

The Principled BSDF that combines multiple layers into a single easy to use node. It is based on the Disney principled model also known as the «PBR» shader, making it compatible with other software such as Pixar’s Renderman^® and Unreal Engine^®. Image textures painted or baked from software like Substance Painter^® may be directly linked to the corresponding parameters in this shader.

This «Uber» shader includes multiple layers to create a wide variety of materials. The base layer is a user controlled mix between diffuse, metal, subsurface scattering and transmission. On top of that there is a specular layer, sheen layer and clearcoat layer.

Nota

The emphasis on compatibility with other software means that it interprets certain input parameters differently from older Blender nodes.

Entradas

Color Base

Diffuse or metal surface color.

Transluminiscencia

Mix between diffuse and subsurface scattering. Rather than being a simple mix between Diffuse and Subsurface Scattering, it acts as a multiplier for the Subsurface Radius.

Subsurface Radius

Distancia promedio que la luz atravesará por debajo de la superficie. Una radio mayor producirá una apariencia más suave, debido a que la luz se esparcirá hacia las sombras y a través del objeto. La distancia de dispersión se especifica de forma separada para cada canal RVA, para posibilitar recrear materiales tales como piel, en los cuales la luz roja se dispersa más que los otros componentes. Los valores X, Y y Z serán mapeados respectivamente a los valores de R, V y A.

Subsurface Color

Subsurface scattering base color.

Subsurface IOR Cycles Only

Índice de refracción para la transluminiscencia.

Subsurface Anisotropy Cycles Only

Controls the directionality of subsurface scattering.

Metálico

Blends between a non-metallic and metallic material model. A value of 1.0 gives a fully specular reflection tinted with the base color, without diffuse reflection or transmission. At 0.0 the material consists of a diffuse or transmissive base layer, with a specular reflection layer on top.

Especularidad

Amount of dielectric specular reflection. Specifies facing (along normal) reflectivity in the most common 0 - 8% range.

Consejo

To compute this value for a realistic material with a known index of refraction, you may use this special case of the Fresnel formula: \(specular = ((ior - 1)/(ior + 1))^2 / 0.08\)

Por ejemplo:

• water: ior = 1.33, specular = 0.25

• glass: ior = 1.5, specular = 0.5

• diamond: ior = 2.417, specular = 2.15

Since materials with reflectivity above 8% do exist, the field allows values above 1.

Specular Tint

Tints the facing specular reflection using the base color, while glancing reflection remains white.

Normal dielectrics have colorless reflection, so this parameter is not technically physically correct and is provided for faking the appearance of materials with complex surface structure.

Rugosidad

Specifies microfacet roughness of the surface for diffuse and specular reflection.

Anisotropía sólo en Cycles

Cantidad de anisotropía para la reflexión especular. Valores mayores (positivos) producirán brillos especulares alargados en dirección tangencial; valores negativos producirán brillos especulares alargados en dirección perpendicular a la dirección tangencial.

Rotación de anisotropía sólo en Cycles

Permite rotar la dirección de la anisotropía, con un valor de 1.0 produciendo un círculo completo.

Consejo

Comparado con el nodo BSDF Anisótropo, la dirección de elongación de los brillos especulares se encuentra rotada 90°. Agregar 0.25 al valor para compensarlo.

Brillo tangencial

Amount of soft velvet like reflection near edges, for simulating materials such as cloth.

Sheen Tint

Mix between white and using base color for sheen reflection.

Barniz

Extra white specular layer on top of others. This is useful for materials like car paint and the like.

Clearcoat Roughness:

Roughness of clearcoat specular.

IR

Index of refraction for transmission.

Transmisión

Mix between fully opaque surface at zero and fully glass like transmission at one.

Transmission Roughness Cycles Only

With GGX distribution controls roughness used for transmitted light.

Emisión

Light emission from the surface, like the Emission shader.

Intensidad de emisión

Strength of the emitted light. A value of 1.0 will ensure that the object in the image has the exact same color as the Emission Color, i.e. make it “shadeless”.

Alfa

Controlará la transparencia de la superficie, con 1.0 siendo completamente opaca. Usualmente conectado a la salida de Alfa de un nodo de textura de Imagen.

Normal

Controla las normales de las capas base.

Clearcoat Normal

Controls the normals of the Clearcoat layer.

Tangente

Controls the tangent for the Anisotropic layer.

Propiedades

Distribución

Tipo de distribución de microfacetas a usar.

GGX:

A method that is faster than Multiple-scattering GGX but is less physically accurate. Selecting it enables the Transmission Roughness input.

Multiple-scattering GGX:

Takes multiple bounce (scattering) events between microfacets into account. This gives a more energy conserving results, which would otherwise be visible as excessive darkening.

Método de transluminiscencia

Métodos de procesamiento para simular la transluminiscencia.

Nota

Eevee does use not support the Random Walk methods.

Christensen-Burley:

Una aproximación a una dispersión volumétrica basada en principios físicos. Este método es menos preciso que Camino aleatorio, sin embargo en algunas situaciones producirá menos ruido en menos tiempo.

Camino aleatorio (Radio fijo):

Provides accurate results for thin and curved objects. Random Walk uses true volumetric scattering inside the mesh, which means that it works best for closed meshes. Overlapping faces and holes in the mesh can cause problems.

Camino aleatorio:

Behaves similarly to Random Walk (Fixed Radius) but modulates the Subsurface Radius based on the Color, Subsurface Anisotropy, and Subsurface IOR. This method thereby attempts to retain greater surface detail and color than Random Walk (Fixed Radius).

Salidas

BSDF

Salida estándar de sombreador.

Ejemplos

Below are some examples of how all the Principled BSDF’s parameters interact with each other.