AOUSD releases the OpenUSD Core Specification
The Alliance for OpenUSD (AOUSD), the organization founded to guide future development of Pixar’s Universal Scene Description, has released the OpenUSD Core Specification 1.0.
The document – the first formal definition of the core algorithms use to construct USD scenes – is a “critical first step” towards making USD an ISO-ratified cross-industry standard.
Future specifications will cover more industry-specific aspects, including the way that geometry, materials and physics are represented in USD data.
A first step towards making USD a standard outside the world of VFX and animation
Formed in 2023, the AOUSD aims to make OpenUSD an ISO ratified standard, and to expand it from an entertainment-industry technology to “embrace the needs of new industries”.
Membership of the organization has now expanded from the original five founder members – Pixar itself, plus Adobe, Apple, Autodesk and NVIDIA – to include a further 45 general members.
As well as CG software developers like Chaos, Epic Games, Foundry, Maxon, Otoy and SideFX, the general members include key players in architecture, construction and manufacturing, retailers like Lowe’s and The Coca-Cola Company, and tech giants like Intel, Microsoft and Sony.
An official framework against which software can be tested for USD compliance
The publication of the OpenUSD Core Specification marks the first milestone on the AOUSD’s original two-year roadmap.
For the AOUSD itself, the specification serves as the official guide for all of future AOUSD projects, providing “canonical documentation for all higher-level [USD] specifications”.
For developers, it provides a framework against which software can be tested to ensure that it is “truly compatible” with the USD standard.
Initial 1.0 spec focuses on core algorithms and the USD file formats
The initial 1.0 specification focuses on the core USD algorithms – how USD scenes are constructed, and how data is represented within them.
It also provides detailed specs for the USD file formats: human-readable USDA files, binary USDC files, and compressed USDZ files, the latter often used in real-time applications.
A 1.1 update, due for release next year, will include more animation features, variable and path expressions, and “scaling capabilities for massive and complex scenes”.
Separate standards will cover geometry, materials and physics
The core spec does not cover what the AOUSD describes as “domain-specific uses”, like the way that geometry, materials or physics are represented, which will addressed by future, more specialized standards.
You can find a more detailed discussion of what the OpenUSD core spec does and does not cover, and what it means for software developers, on the AOUSD blog.
Read the OpenUSD Core Specification 1.0
Read the AOUSD’s blog post discussing what the core spec means for users
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