Version 1.39.0

Added

• Added support for the OpenPBR Surface shading model, including the MaterialX definition and example materials for OpenPBR Surface v1.1.
• Added support for Hoffman-Schlick Fresnel, Zeltner sheen, and energy-compensated Oren-Nayar diffuse, with initial implementations in hardware shading languages.
• Added support for the LamaGeneralizedSchlick and LamaIridescence nodes, with definitions provided as MaterialX graphs.
• Added support for integer-type add, subtract, and conditional nodes.
• Added support for matrix-type switch and conditional nodes.
• Added support for additional convert node input and output types.
• Added support for monolithic builds of MaterialX.
• Added support for the full set of shader generators in JavaScript.
• Added support for frame timing in the MaterialX Viewer.
• Added a uiScale option for adjusting DPI in the Graph Editor.
• Added an example script to generate a MaterialX document from a folder of textures.
• Added unit tests for core utilities and ESSL shader generation.
• Added support for Python 3.12 in Python wheel generation.
• Added GCC 14 and Clang 18 builds to GitHub Actions CI.

Changed

• Raised the minimum C++ version for MaterialX builds to C++17.
• Updated the PyBind11 library to version 2.12.0, enabling support for recent compilers and CMake versions.
• Improved the expression of thin-film layering in MaterialX 1.39, with automatic upgrade logic for legacy documents.
• Improved the generality of the normalmap node in MaterialX 1.39, with automatic upgrade logic for legacy documents.
• Extended the switch node to ten inputs in MaterialX 1.39, with automatic upgrade logic for legacy documents.
• Renamed the inputs of the atan2 node in MaterialX 1.39, with automatic upgrade logic for legacy documents.
• Changed the type of subsurface_bsdf radius from vector3 to color3 in MaterialX 1.39, with automatic upgrade logic for legacy documents.
• Renamed the normalmap nodedef in MaterialX 1.39, with automatic upgrade logic for legacy documents.
• Improved the support for double-sided materials in MaterialX 1.39.
• Optimized Fresnel computations in GLSL, improving the performance of physically based shading in real-time renders.
• Applied lossless optimization to PNG and JPG textures in the MaterialX repository.

Fixed

• Fixed default values for the creatematrix node.
• Fixed an issue with keyboard input focus in the Graph Editor.

Removed

• Removed the swizzle node in MaterialX 1.39, with automatic upgrade logic for legacy documents.
• Removed the channels attribute in MaterialX 1.39, with automatic upgrade logic for legacy documents.
• Removed the unimplemented arrayappend node in MaterialX 1.39.