Reference/Release Notes/4.0/Shading

Shading & Texturing

Principled BSDF

The Principled BSDF node has been revamped to support a wide ranger of material types.

  • Sheen uses a new microfiber shading model, and is the top layer above emission and coat. Traditionally sheen has been used for fuzzy cloth, but now it can also be used for dust on arbitrary materials.
  • Coat was placed above the emission layer. This can be used to simulate for example an emissive phone screen behind glass. Coat tint and IOR inputs were added, so that it can be used for more than a white clearcoat.
  • Subsurface scattering uses the base color instead of a separate color input. There is a new subsurface scale input to adjust the RGB radius.
  • Specular reflection and transmission are now primarily controlled by a single index of refraction input. For texturing, a new IOR Level input adjust the amount of specular reflection. For artistic purposes, specular tint be can set to an arbitrary color.
  • Metallic surfaces gained edge tinting using the specular tint input. This is an artist friendly parameter to render complex index of refraction, based on the F82 tint model.
  • Multiple scattering GGX is more efficient to render in Cycles, and now used by default. Layering of the components as a whole is more energy conserving, which means existing materials can render slightly darker or lighter depending on the scene.

See the Principled BSDF manual page for details.

Using sheen to add a layer of dust.
Scene by Alaska using assets from Poly Haven.
Metallic tint from white to orange, for materials like gold.
Coat tint from white to blue, for materials like car paint.

BSDF Nodes

  • The Glossy and Anisotropic BSDF were merged into a single Glossy BSDF with anisotropy control. When opening files saved in 4.0 in older versions, all "Glossy BSDF" nodes will show up as Anisotropic BSDF nodes. (8cde7d8f8a)
  • Normal Map now has better interpolation for the Strength input for tangent space normal maps, avoiding the normal going below the surface for strength larger than 1. This changes the looks of existing renders where Strength was not 1. (PR #109763)
  • The Velvet BSDF node has been renamed to Sheen BSDF, and a new shading model ("Microfiber") has been added as the default option. The previous model is still available as "Ashikhmin", so existing files remain unchanged. (PR #108869)

Texture Nodes

Noise Texture

New inputs for the Noise Texture node, which generates fractal Perlin noise. (0702c24a36)

  • Normalize: normalize output to be within 0..1 range. This is most useful for colors or blending factors, while bump or displacement does not need it.
  • Lacunarity: the factor each successive layer is scaled with.

Voronoi Texture

The Voronoi Texture node has support for fractal noise now, to add multiple layers of details. There are 3 new inputs. (144ad4d20b)

  • Detail: number of layers to compute.
  • Roughness: how much influence the higher layers have on the final output
  • Lacunarity: the factor each successive layer is scaled with.

Additionally a "Normalize" property was added, which if checked will remap the Distance and Color outputs to a [0.0, 1.0] range.

Detail 1.0, 2.0 and 4.0
F1 Detail 1.png
F1 Detail 2.png
F1 Detail 4.png
Roughness 0.25, 0.5 and 1.0
F1 Roughness 025.png
F1 Roughness 05.png
F1 Roughness 1.png
Lacunarity 2.0, 4.0 and 8.0
F1 Lacunarity 2.png
F1 Lacunarity 4.png
F1 Lacunarity 8.png


  • Light UV is now available for all light sources in Image Texture node (#108691)
  • Light sources have slightly different behaviours than before for energy preservation and better compatibility with other renders #108505, including:
    • Point light and spot light are changed to double-sided sphere lights (#108506 #109329). Besides, the light normal now points from light center to the sampled/intersected position on the sphere, any pipeline that was using the light normal should use the Incoming socket of the Geometry shader node instead.
    • Sun light behaves better at large angular diameters, and gives the same intensity regardless of the angular diameter. (#108996)
    • Corrected conversion factor for area lights (482211b7e0)