Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] General Discussion => Topic started by: zaar on 2025-04-28, 10:16:04

Title: OpenPBR Material
Post by: zaar on 2025-04-28, 10:16:04
Hello!

Since of 3ds Max 2026, the standard material in Max is now OpenPBR Material. I'm not using 2026 in production yet, but this has sparked my curiosity and I would like to know if there is official documentation on what is supported and not in Corona?

After some breif testing it seems some parts work while there are some stuff that doesn't work as expected, much like the old Physical material. It's nice that it renders anyway. But are there plans to fully support it?

This would be really good since this looks like a material a lot of applications will support. And this would allow for building of assets and working in Corona, while still having to option to move things to other DCCs.

Also fully supporting it would mean implementing thinfilm, which doesn't make much difference to me right now, but I know it's been requested before.
Title: Re: OpenPBR Material
Post by: Aram Avetisyan on 2025-04-28, 12:28:29
Hi,

What exactly you think does not work in Corona in regards to OpenPBR material?
Please post the examples here to better understand the case.
Title: Re: OpenPBR Material
Post by: zaar on 2025-04-28, 13:50:40
I noticed that specular weight and thinfilm doesn't work so far, and that got me wondering. I don't plan on checking everything and making a list, I was hoping that team corona has a list ;)
Title: Re: OpenPBR Material
Post by: Aram Avetisyan on 2025-04-28, 14:34:06
I noticed that specular weight and thinfilm doesn't work so far, and that got me wondering. I don't plan on checking everything and making a list, I was hoping that team corona has a list ;)

If there is direct analogous parameter in CoronaPhysicalMtl, then it will/is expected to be supported. CoronaPhysicalMtl does not have reflection level or map (like in CoronaMtl/CoronaLegacyMtl). Instead, the reflectivity is controlled through IOR/Specular and roughness - relfection weight and color are assumed to be full/white.
E.g. there is no diffuse roughness in CoronaPhysicalMtl too, so that (alongside with Thin film, for now, and other channels) is not supported either. After all, PhysicalMtl and OpenPBD, the new standard, are being interpreted as CoronaPhysicalMtl as good as possible.