Academy Software Foundation Announces OpenPBR, a New Subproject of MaterialX | Hacker News Reader

Academy Software Foundation Announces OpenPBR, a New Subproject of MaterialX

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36 pointsfranzb10 comments

Since this topic may not be familiar to many on here:

MaterialX (https://materialx.org/ ) is a node graph based way to author the surface characteristics of 3D models. It also has shader code generation capabilities for GLSL(OpenGL), MDL(NVIDIA), OSL(OpenShadingLanguage) and MSL(Apples Metal). It was created by Industrial Light and Magic for the new Star Wars trilogy and allows them to abstract the shader definition from the rendering backend. E.g you have the same shader for real-time and offline renderers.

OpenPBR is a shading model (or more accurately a BSDF https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4930030/ ) within MaterialX. It’s the successor of shading models from Autodesk and Adobe who combined their work to make one consistent one.

MaterialX support across the industry is growing. Multiple renderers support it, Blender has a PR in progress courtesy of AMD, Apple use it for their shadergraph for VisionOS development just to name a few.

My understanding is that this is an evolution of the Autodeks Standard Surface (https://autodesk.github.io/standard-surface/), which itself is a superset of the glTF 2.0 material with its PBR extensions (https://github.com/KhronosGroup/glTF/blob/main/extensions/RE... ). This OpenPBR is designed to handle Hollywood VFX type effects as well as real-time, thus it is more complex than glTF's PBR materials which are real-time focused.

Together this means there is a lot of alignment between these models. I wouldn't be surprised to see a glTF 3.0 that adopts the OpenPBR as its main material definition, skipping the current extension complexity.

OpenPBR for material exchange combined with MaterialX for shader graph exchange combined (https://materialx.org) with OpenUSD for geometry and scene graph exchange, means together we are headed into a world where high quality 3D assets are exchangeable between content creation tools.

This is an evolution and merger of the Autodesk Standard Surface and Adobe Standard Surface.

Edit: removed mention of subset/superset since his post corrected the typo

But yes there’s overlap as there will be in any PBR definition and I think the glTF spec can be considered a subset of this, closer to the preview variant.

NOTE: I fixed the typo, it was intended to be "superset" rather than "subset."

Awesome. I updated my post accordingly too

The current headline is meaningless to someone not into computer graphics/rendering.

That's fair, but so are many headlines to people not intimately involved with the corresponding projects or tech stacks :)

HN policy, for better or worse, is to copy the headline from the article exactly. In my experience any tweaks to the title just get reverted by the mods.

I clicked on this after my brain told me that PBR stands for policy-based routing

I had a hunch it was not going to be about Pabst Blue Ribbon, but I clicked the link anyway.

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