Principled BSDF

Principled BSDF node.

The Principled BSDF that combines multiple layers into a single easy to use node. It can model a wide variety of materials.

It is based on the OpenPBR Surface shading model, and provides parameters compatible with similar PBR shaders found in other software, such as the Disney and Standard Surface models. Image textures painted or baked from software like Substance Painter may be directly linked to the corresponding input in this shader.

Слои

The base layer is a mix between metal, diffuse, subsurface, and transmission components. Most materials will use one of these components, though it is possible to smoothly mix between them.

../../../_images/render_shader-nodes_principled_layers.svg

The metal component is opaque and only reflect lights. Diffuse is fully opaque, while subsurface also involves light scattering just below the surface. Both diffuse and subsurface sit below a specular layer. The transmission component includes both specular reflection and refraction.

On top of all base layers there is an optional glossy coat. And finally the sheen layer sits on top of all other layers, to add fuzz or dust.

Light emission can also be added. Light emits from below the coat and sheen layers, to model for example emissive displays with a coat or dust.

Входы

Base Color

Overall color of the material used for diffuse, subsurface, metal and transmission.

../../../_images/render_shader-nodes_shader_principled-base-color.webp

Same base color for multiple materials types

Roughness (шероховатость)

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

../../../_images/render_shader-nodes_shader_principled-roughness.webp

Roughness from 0.0 to 1.0

Metallic

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

../../../_images/render_shader-nodes_shader_principled-metallic.webp

Metallic from 0.0 to 1.0

IOR

Index of refraction for specular reflection and transmission.

../../../_images/render_shader-nodes_shader_principled-ior.webp

IOR from 1.0 to 2.0

Alpha

Controls the transparency of the surface, with 1.0 fully opaque. Usually linked to the Alpha output of an Image Texture node.

../../../_images/render_shader-nodes_shader_principled-alpha.webp

Alpha from 0.0 to 1.0

Normal

Controls the normals of the base layers.

Subsurface

Subsurface scattering is used to render materials such as skin, milk and wax. Light scatters below the surface to create a soft appearance.

Method

Rendering method to simulate subsurface scattering.

Christensen-Burley (Кристенсен-Бурлей):

An approximation to physically-based volume scattering. This method is less accurate than Random Walk however, in some situations this method will resolve noise faster.

Random Walk:

Cycles Only 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.

Random Walk (Skin):

Cycles Only Random walk method optimized for skin rendering. The radius is automatically adjusted based on the color texture, and the subsurface entry direction uses a mix of diffuse and specular transmission with custom IOR. This tends to retain greater surface detail and color and matches measured skin more closely.

Weight (вес)

Blend between diffuse surface and subsurface scattering. Typically should be zero or one (either fully diffuse or subsurface)

../../../_images/render_shader-nodes_shader_principled-subsurface-weight.webp

Weight from 0.0 to 1.0

Radius (радиус)

Average distance that light scatters below the surface. Higher radius gives a softer appearance, as light bleeds into shadows and through the object. The scattering distance is specified separately for the RGB channels, to render materials such as skin where red light scatters deeper. The X, Y and Z values are mapped to the R, G and B values, respectively.

../../../_images/render_shader-nodes_shader_principled-subsurface-radius.webp

Radius from white to red

Scale (масштаб)

Scale applied to the radius.

../../../_images/render_shader-nodes_shader_principled-subsurface-scale.webp

Scale from 0 cm to 50 cm

IOR Cycles Only

Index of refraction used for rays that enter the subsurface component. This may be set to a different value than the global IOR to simulate different layers of skin.

../../../_images/render_shader-nodes_shader_principled-subsurface-ior.webp

IOR from 1.0 to 2.0

Anisotropy Cycles Only

Directionality of volume scattering within the subsurface medium. Zero scatters uniformly in all directories, with higher values scattering more strongly forward. For example skin has been measure to have an anisotropy of 0.8.

../../../_images/render_shader-nodes_shader_principled-subsurface-anisotropy.webp

Anisotropy from 0.0 to 1.0

Specular

Controls for both the metallic component and specular layer on top of diffuse and subsurface.

Распределение

Используемое распределение микрограней.

GGX:

A method that is faster than Multiple-scattering GGX but is less physically accurate.

Multiscatter GGX:

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

IOR Level

Adjustment to the IOR to increase or decrease intensity of the specular layer. 0.5 means no adjustment, 0 removes all reflections, 1 doubles them at normal incidence.

This input is designed for conveniently texturing the IOR and amount of specular reflection.

../../../_images/render_shader-nodes_shader_principled-specular-ior-level.webp

IOR level from 0.0 to 1.0

Tint

Color tint for specular and metallic reflection.

For non-metallic tints provides artistic control over the color specular reflections at normal incidence, while grazing reflections remain white. In reality non-metallic specular reflection is fully white.

For metallic materials tints the edges to simulate complex IOR as found in materials such as gold or copper.

../../../_images/render_shader-nodes_shader_principled-specular-tint.webp

Tint from white to orange

Anisotropic Cycles Only

Amount of anisotropy for specular reflection. Higher values give elongated highlights along the tangent direction; negative values give highlights shaped perpendicular to the tangent direction.

../../../_images/render_shader-nodes_shader_principled-specular-anisotropic.webp

Anisotropic from 0.0 to 1.0

Anisotropic Rotation Cycles Only

Rotates the direction of anisotropy, with 1.0 going full circle.

Compared to the Anisotropic BSDF node, the direction of highlight elongation is rotated by 90°. Add 0.25 to the value to correct.

../../../_images/render_shader-nodes_shader_principled-specular-anisotropic-rotation.webp

Anisotropic rotation from 0.0 to 1.0

Tangent

Controls the tangent for the Anisotropic layer.

Transmission

Transmission is used to render materials like glass and liquids, where the surface both reflects light and transmits it into the interior of the object

Weight (вес)

Mix between fully opaque surface at zero and fully transmissive at one.

../../../_images/render_shader-nodes_shader_principled-transmission-weight.webp

Weight from 0.0 to 1.0

Coat

Coat on top of the materials, to simulate for example a clearcoat, lacquer or car paint.

Weight (вес)

Controls the intensity of the coat layer, both the reflection and the tinting. Typically should be zero or one for physically-based materials, but may be textured to vary the amount of coating across the surface.

../../../_images/render_shader-nodes_shader_principled-coat-weight.webp

Weight from 0.0 to 1.0

Roughness (шероховатость)

Roughness of the coat layer.

../../../_images/render_shader-nodes_shader_principled-coat-roughness.webp

Roughness from 0.0 to 1.0

IOR

Index of refraction of the coat layer. Affects its reflectivity as well as the falloff of coat tinting.

../../../_images/render_shader-nodes_shader_principled-coat-ior.webp

IOR from 1.0 to 2.0

Tint

Adds a colored tint to the coat layer by modeling absorption in the layer. Saturation increases at shallower angles, as the light travels farther through the medium, depending on the IOR.

../../../_images/render_shader-nodes_shader_principled-coat-tint.webp

Tint from white to blue

Normal

Controls the normals of the Coat layer, for example to add a smooth coating on a rough surface.

Sheen

Sheen simulates very small fibers on the surface. For cloth this adds a soft velvet like reflection near edges. It can also be used to simulate dust on arbitrary materials.

Weight (вес)

Controls in the intensity of the sheen layer.

../../../_images/render_shader-nodes_shader_principled-sheen-weight.webp

Weight from 0.0 to 1.0

Roughness (шероховатость)

Roughness of the sheen reflection.

../../../_images/render_shader-nodes_shader_principled-sheen-roughness.webp

Roughness from 0.0 to 1.0

Tint

The color of the sheen reflection.

../../../_images/render_shader-nodes_shader_principled-sheen-tint.webp

Tint from white to green.

Emission

Light emission from the surface.

Color

Color of light emission from the surface.

../../../_images/render_shader-nodes_shader_principled-emission-color.webp

Emission color variations

Strength (сила)

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“.

../../../_images/render_shader-nodes_shader_principled-emission-strength.webp

Strength from 0.0 to 10.0

Выходы

BSDF

Стандартный выход шейдера.