Third-Party MaterialX Support
A number of third-party systems and packages support MaterialX, or are working to add support for MaterialX in the future. We will add descriptions to the list below as these efforts are made public.
MaterialX Standard Node OSL Shaders
The MaterialX specification expects material node operators to have the exact same mathematical behavior regardless of which context or package they're evaluated in. To remove any interpretation ambiguity in how operators should be computed, OSL code has been provided for most MaterialX nodes and is included with the MaterialX distribution. Many thanks to Adam Martinez and Derek Haase for this contribution.
Substance Designer MaterialX Plugin
The Substance team at Adobe has released a plugin for Substance Designer 2020.1 to build procedural texture shaders and StandardSurface-based surface shaders in Substance Designer and export as MaterialX files. Note that this plugin is still Beta software and may not be ready for production use.
They have also posted a Getting Started with MaterialX in Substance Designer video on YouTube.
MaterialX Operator in Arnold
Arnold has a MaterialX Operator node, which can be used to apply materials, property assignments, visibility from a MaterialX Look file. The Arnold MaterialX operator works in all DCCs that Arnold supports.
USD / MaterialX (Pixar)
Lucasfilm and Pixar are working toward full compatibility between MaterialX and USD, so that MaterialX node graphs and assignments can be fully encoded in USD within the USDShade schema. This allows systems to take advantage of USD scene composition features for MaterialX-compliant networks via direct references to .mtlx files within USD files and automatic on-the-fly conversion of supported content in MaterialX documents to USDShade.
USD currently supports direct references to MaterialX .mtlx files within USD scenes, with supported content automatically translated to UsdShade, although rendering of MaterialX networks within Hydra is not yet supported.