BSDF Nguyên Tắc -- Principled BSDF

Principled BSDF.

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.

Ghi chú

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

Đầu Vào -- Inputs

Màu Cơ Sở -- Base Color

Diffuse or metal surface color.

Dưới Bề Mặt -- Subsurface

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.

Bán Kính của Lớp Dưới Bề Mặt -- Subsurface Radius

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.

Màu Dưới Bề Mặt -- Subsurface Color

Subsurface scattering base color.

Kim Loại -- Metallic

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.

Lóng Lánh -- Specular

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

Gợi ý

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

Ví dụ:

• 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.

Sắc Thái của Lóng Lánh -- 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.

Độ Ráp -- Roughness

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

Gợi ý

When converting from the older Glossy BSDF node, use the square root of the original value.

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.

Anisotropic Rotation Cycles Only

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

Gợi ý

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

Bóng Bảy -- Sheen

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

Sắc Thái của Bóng Bảy -- Sheen Tint

Mix between white and using base color for sheen reflection.

Lớp Sơn Bóng -- Clearcoat

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.

Chỉ Số Khúc Xạ (IOR) -- IOR

Index of refraction for transmission.

Truyền Xạ -- Transmission

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.

Emission

Light emission from the surface, like the Emission shader.

Emission Strength

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'.

Alpha

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

Pháp Tuyến -- Normal

Controls the normals of the base layers.

Pháp Tuyến của Lớp Sơn Bóng -- Clearcoat Normal

Controls the normals of the Clearcoat layer.

Tiếp Tuyến -- Tangent

Controls the tangent for the Anisotropic layer.

Tính Chất -- Properties

Phân Phối -- Distribution

Microfacet distribution to use.

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.

Phương Pháp Dưới Bề Mặt -- Subsurface Method

Rendering method to simulate subsurface scattering.

Christensen-Burley

Is an approximation to physically-based volume scattering. Gives less blurry results than Cubic and Gaussian functions.

Tiến Bước Ngẫu Nhiên -- Random Walk

Provides the most accurate results for thin and curved objects. This comes at the cost of increased render time or noise for more dense media like skin, but also better geometry detail preservation. 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.

Đầu Ra -- Outputs

BSDF

Đầu ra chuẩn của bộ tô bóng.

Ví Dụ -- Examples

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