Support for MaterialX Export and Integration

[ymozer]

Feature/enhancement description:

From MaterialX website:

MaterialX addresses the need for a common, open standard to represent the data values and relationships required to describe the look of a computer graphics model, including shading networks, patterns and texturing, complex nested materials and geometric assignments. To further encourage interchangeable CG look setups, MaterialX also defines a large set of standard shading and processing nodes with a precise mechanism for functional extensibility.

Currently, Material Maker is a great tool for generating textures for Godot, Unity, and Unreal. However, users working in VFX, animation, or rendering pipelines (using Houdini, Maya, Arnold, Karma, RenderMan or custom engines) have to manually reconnect exported PNGs/EXRs into their respective softwares.

By supporting MaterialX (.mtlx), Material Maker could output a standardized material description alongside its baked textures, allowing for true "one-click" import into almost any modern 3D pipeline.

User benefits & Use Cases:

• Users could export a material and instantly load it into softwares supporting MaterialX without manually reconstructing the PBR shader network.

• MaterialX's standard_surface specification ensures that a material authored in Material Maker looks exactly the same across different industry-standard renderers.

• With the Academy Software Foundation (ASWF) backing MaterialX, and major engines adopting it as a primary material format, supporting it increases Material Maker's supported platforms automatically.

Additional Context:

MaterialX Github Repo
MaterialX Standard Surface Specification