Do we want to support alternative BRDF?

[patriciogonzalezvivo]

@shadielhajj have you seen this https://arxiv.org/pdf/2410.18026 ??

[patriciogonzalezvivo]

https://dassaultsystemes-technology.github.io/EnterprisePBRShadingModel/spec-2025x.md.html

[shadielhajj]

Excellent stuff thanks @patriciogonzalezvivo.

We currently don't have diffuse roughness implemented in our PBR pipeline (as opposed to specular roughness). It's quite costly and it's typically used in high-end pathtracers such as Octane. I am not aware of any real-time engine that implements it, as Brian Karis (Unreal), Romain Guy (Filament) and others have concluded it's not worth the extra cost. But it's def interesting to keep an eye on it, especially given that the model you reference is actually energy-conserving.

I didn't know about the Dassault PBR shading model thanks for sharing. Looks very interesting, and I'll study it.
My long-term plan is to implement the OpenPBR model which is a synthesis of the Autodesk Standard Surface (currently the de-facto standard) and the Adobe Standard Material models. OpenPBR has been adopted by the Academy Software Foundation and is a sub-project of MaterialX, which is slowly being adopted as the standard material and look-dev definition language.

Happy to keep the conversation around shading models flowing in this thread!

[patriciogonzalezvivo]

That's fantastic! love that vision.

Note: I have been working closer to the Adobe Substance team, so eventually we could ping them <3 I feel they will love to see how you have been leading that effort and the results

[shadielhajj]

Sounds great @patriciogonzalezvivo. The Adobe Substance team is quite involved in OpenPBR. Let's def reach out to them when we think we have something to show!