Monday, November 6th, 2023 Posted by Jim Thacker

ASWF, Adobe, Autodesk launch OpenPBR

Originally posted on 3 August 2023, and updated with details of the public release.

VFX industry standards body the Academy Software Foundation (ASWF) has announced OpenPBR, a subproject of MaterialX, the open material standard it maintains.

Created by Adobe and Autodesk with “guidance from the MaterialX Technical Steering Committee”, the open-source shading model will replace the Adobe Standard Material and Autodesk Standard Surface.

When launched publicly, OpenPBR should increase interoperability of materials between CG software, with any tool that supports MaterialX supporting OpenPBR automatically.

Unifiying Adobe and Autodesk’s internal material standards
At the minute, Adobe and Autodesk maintain separate, but parallel, technical specifications for 3D materials: the Adobe Standard Material and Autodesk Standard Surface.

Both are intended to streamline look development and rendering by making it possible to transfer materials between applications, with materials displaying near-identically in each app.

Both also draw on many of the same sources, including Disney’s Principled Shader and Allegorithmic’s PBR shading model, with Adobe even citing the Autodesk Standard Surface as an influence.

However, at present, both are really only supported in the developers’ own software: in the case of Autodesk Standard Surface, Arnold, 3ds Max and Maya, for Adobe Standard Material, the Substance 3D tools.

Automatically supported in any application that supports MaterialX
OpenPBR should unify the two models, making it possible for materials to display consistently across Adobe and Autodesk software.

In fact, materials should display consistently in a much wider range of apps, since OpenPBR is a sub-project of open standard MaterialX, supported in a range of CG software, including Houdini, RenderMan and UE5.

MaterialX materials are also supported in Blender via AMD’s USD Hydra plugin.

At launch, a reference implementation of OpenPBR will be available in MaterialX, meaning that “anything that already supports MaterialX will automatically support OpenPBR”.

A demo scene shaded using OpenPBR and rendered in Arnold for Maya by Nikie Monteleone.

Updated 6 November 2023: OpenPBR has now been released publicly.

The initial release, OpenPBR 0.2, includes the specification for the OpenPBR Surface shading model and source code for the reference implementation, written in MaterialX.

Licence and system requirements
The OpenPBR specification and source code for the reference implementation are available on GitHub under an open-source Apache 2.0 licence.

Read the Academy Software Foundation’s blog post announcing OpenPBR

Download the specification and reference implementation for OpenPBR from GitHub

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