The purpose of this article is to guide you through Sketchfab's implementation of PBR, as well as the Sketchfab material editor. It is not intended to teach you how to use PBR in general. There are many great resources on PBR theory and practice, including Allegorithmic's PBR Guide.
What is PBR?
Physically Based Rendering (PBR) is a method of shading and rendering that provides a more accurate representation of how light interacts with surfaces. It can be referred to as Physically Based Rendering (PBR) or Physically Based Shading (PBS). Depending on what aspect of the pipeline is being discussed, PBS is usually specific to shading concepts and PBR specific to rendering and lighting. However, both terms describe on a whole, the process of representing assets from a physically accurate standpoint. - Wes McDermott, Allegorithmic PBR Guide, Vol. 2
PBR is a methodology, not necessarily a hard standard.
PBR on Sketchfab
The PBR material tools are available in 3D Settings.
- From your model, click Edit 3D Settings or add "/edit" to the end of any model URL.
- Select the Materials panel in the top left.
See also Materials and Textures.
PBR has two main workflow options: Metalness and Specular. See PBR Maps.
Anisotropic reflections are stretched across a surface due to patterned roughness on that surface. Some common use cases are hair and brushed steel. See Anisotropy.
Roughness / Glossiness
The Roughness or Glossiness channel describes a material's surface irregularities and how they affect the reflection of light. See Roughness / Glossiness.
The Displacement channel can move a model's vertices. See Displacement.
Normal Map / Bump Map
The normal map or bump map channel adds bumps, dents, and other details to the surface of a model. See Normal Map / Bump Map.
The Sheen channel simulates the way light interacts with lots of small threads which absorb and scatter colors. See Sheen.
Subsurface Scattering / Skin
The Subsurface scattering (SSS) channel simulates the effect of light scattering inside an object. It is useful for translucent materials like skin, wax, and ice. See Subsurface Scattering / Skin.
The Clear Coat channel simulates the effect of a thin reflective layer on top of a surface. A common use case is the transparent coating on top of car paint. See Clear Coat.
Ambient Occlusion (AO)
The Ambient Occlusion (AO) channel defines large areas of occluded light. See Ambient Occlusion (AO).
The Cavity channel defines small areas of occluded light. See Cavity.
Transparency / Opacity / Alpha Mask
Sketchfab supports several transparency modes: Blending, Refraction, Additive, Dithered, and Mask.
See Transparency for details.
The Emission channel can make a material glow. See Emission.
The Faces Rendering option allows you to display just one, or both, sides of a material surface. See Faces Rendering.
Once you've made your adjustments, including position and orientation, be sure to update your model's thumbnail image and default position with Save View and/or save your changes with Save Settings. You can return to your model by clicking either the model's name or Exit.