pbrappearance.md

PBRAppearance

PBRAppearance {
  SFColor  baseColor            1 1 1             # any color
  SFNode   baseColorMap         NULL              # {ImageTexture, PROTO}
  SFFloat  transparency         0                 # [0, 1]
  SFFloat  roughness            0                 # [0, 1]
  SFNode   roughnessMap         NULL              # {ImageTexture, PROTO}
  SFFloat  metalness            1                 # [0, 1]
  SFNode   metalnessMap         NULL              # {ImageTexture, PROTO}
  SFFloat  IBLStrength          1                 # [0, inf)
  SFNode   normalMap            NULL              # {ImageTexture, PROTO}
  SFFloat  normalMapFactor      1                 # [0, inf)
  SFNode   occlusionMap         NULL              # {ImageTexture, PROTO}
  SFFloat  occlusionMapStrength 1                 # [0, inf)
  SFColor  emissiveColor        0 0 0             # any color
  SFNode   emissiveColorMap     NULL              # {ImageTexture, PROTO}
  SFFloat  emissiveIntensity    1                 # [0, inf)
  SFNode   textureTransform     NULL              # {TextureTransform, PROTO}
  SFString name                 "PBRAppearance"   # any string
}

Description

%figure "An Oxidised Copper Sphere made with the PBRAppearance node"

%end

The PBRAppearance node specifies a physically-based visual appearance of a node. The acronym "PBR" refers to "Physically-Based Rendering", a term used to designate a class of shading models based on the physical properties of an object, as opposed to more archaic models such as the Blinn-Phong BRDF, used in the Appearance node.

This modern technique enables highly realistic rendering for every kind of object, in any kind of lighting environment.

For a detailed guide on PBR and how to use it for content creation and model design, an excellent description of the concepts on this subject can be found on this blog post by Marmoset.

Our PBR shading model makes use of Lambertian Diffuse, Cook-Torrence Specular and Fresnel-Schlick GGX for direct illumination, and an advanced Image-Based Lighting (IBL) BRDF for ambient diffuse lighting and reflections.

PBRAppearance cannot be used in a Shape node containing an IndexedLineSet or PointSet node.

Field Summary

• The baseColor field specifies the base color or "albedo" of the material's surface, analogous to the diffuseColor field of the Material node.
• The baseColorMap field specifies an ImageTexture for the material's albedo which overrides baseColor.
• The transparency field specifies the transparency of the object. If transparency is non-zero, the object no longer casts shadows.
• The roughness field specifies the roughness of the material's surface, analogous to the inverse of the shininess field of the Material node. A roughness of 0 gives a perfectly smooth material, while a roughness of 1 gives a highly rough material.
• The roughnessMap field specifies an ImageTexture for the material's roughness which overrides roughness.
• The metalness field specifies how metallic the material's surface is. A metalness of 0 gives a completely dielectric material, while a metalness of 1 gives a completely metallic material. Note: it is encouraged to use either 1 or 0 for this value as no real-world materials are partly metallic.
• The metalnessMap field specifies an ImageTexture for the material's metalness which overrides metalness.
• The IBLStrength field specifies a scale factor to be applied to the light contribution from the Background.
• The normalMap field specifies an ImageTexture which is used to peturb the normal vectors of each vertex to create the appearance of relief on flat surfaces, or to add extra detail to low-polycount meshes.
• The normalMapFactor field is used to scale the effect of the normal map on the object.
• The occlusionMap field specifies an ImageTexture which contains pre-baked information about how parts of the model occlude each other (ambient occlusion). This can be used for more realistic-looking lighting.
• The occlusionMapStrength field is used to scale the effect of the occlusion map on the object.
• The emissiveColor field specifies the emissive color of the material's surface (as if the surface emits light), analogous to the emissiveColor field of the Material node.
• The emissiveColorMap field specifies an ImageTexture for the material's emissive color which overrides emissiveColor.
• The emissiveIntensity field is used as an intensity multiplier on the emissive color, to express different emissive brightness levels.
• The textureTransform field contains a TextureTransform node. If textureTransform is NULL, the textureTransform field has no effect. Otherwise, the TextureTransform is applied to all textures in the PBRAppearance node when shading the object.
• The name field is used to give a unique identifier to a PBRAppearance node such that if it is included in an MFNode field it can be retrieved by this name. This name is not required to be unique if the PBRAppearance node is inserted into an SFNode field.