Hi,
We’re working on upgrading our BJS version to 4.2.0-beta.9, getting ready for the November release. We noticed that our textures are not rendering the same between versions:
The images below are from a playground we created: https://playground.babylonjs.com/#KDWCZY#26.
with version 4.1:
and with version 4.2-beta.9:
We’re not sure what might be causing this. Any ideas?
Thanks!
Adding @Evgeni_Popov who might be able to help on this.
There has been a breaking change regarding the value of indexOfRefraction, see the corresponding section here: Babylon.js/what's new.md at master · BabylonJS/Babylon.js · GitHub
It seems setting 1.8 for indexOfRefraction in 4.2 will you get the same display than in 4.1 with a value of 1 but @sebavan will know more about this.
Actually setting an indexOfRefraction to 1 was before having no impact which is not usual and was a bug. The easiest in your case should be to not set it at all 
Can you explain this a little further? I’m unclear what the root-level IOR does that is different in the shader than the subsurface IOR or the subsurface volume IOR? I think we only set the root-level IOR in an attempt to get the two textures to look the same in both versions of Babylon.
I’m also noticing a difference in the metallic workflow. The metallicF0Factor seems to have a lesser effect as well. Is this expected?