Energy conservation solution is a half measure

[^Lele^]

As of beta 2 there has been no change whatsoever to GTR energy preservation.
It's still off by default on shaders, and refraction hasn't changed.
It also works just fine with metallicity for me (see attached furnace test).
The next beta will have fixes and it ought to be enabled by default.

EDIT: the parameter, as a reminder, is

.option_gtrEnergyCompensation

EDIT 2: The parameter is OFF for material editor materials present in a new scene, it's ON by default for newly created shaders. This will be fixed for the next beta. The rest of the info is valid, however.

[kosso_olli]

As of beta 2 there has been no change whatsoever to GTR energy preservation.
It's still off by default on shaders, and refraction hasn't changed.

But why is the refraction looking so much better with 6 on the frozen glass shaders balls in Jonas's tests?

[^Lele^]

No idea: in both cases (on/off) it sums to about 90% energy, so it's not exactly preserving (see how the reflective spheres "disappear" into the white BG instead.).
I have spoken to the relevant dev that kindly confirmed they fixed a bug, and that the option is on for both energy preservation and the new metal fresnel.
This makes me realise that in my tests i had turned on manually only preservation, so perhaps i was getting the right EP without the new Fresnel.
I need to check this out.

EDIT: nope, metallicity works fine even for newly created materials, for me.
If JonasNöll wanted to share a misbehaving scene, we'd be grateful.

[flat]

As of Bata2, the 3dsmax custom UI default (max.vray), Material Editor Material (medit.mat), has .option_gtrEnergyCompensation disabled.

C:\ProgramData\Autodesk\ApplicationPlugins\VRay3ds Max2023\defaults\Max.vray\FactoryDefaults\medit.ma ｔ

[^Lele^]

Thanks for the report.
We're aware of it and the fix will be forthcoming.

[JonasNöll]

No idea: in both cases (on/off) it sums to about 90% energy, so it's not exactly preserving (see how the reflective spheres "disappear" into the white BG instead.).
I have spoken to the relevant dev that kindly confirmed they fixed a bug, and that the option is on for both energy preservation and the new metal fresnel.
This makes me realise that in my tests i had turned on manually only preservation, so perhaps i was getting the right EP without the new Fresnel.
I need to check this out.

EDIT: nope, metallicity works fine even for newly created materials, for me.
If JonasNöll wanted to share a misbehaving scene, we'd be grateful.

I just double checked and it seems that the latest V-Ray 5 Update 2.3 renders the scene with the glass ball totally identical with V-Ray 6 Beta 2. The picture that I rendered the scene with the glass ball looking not correct was V-Ray 5 Update 1. Seems there was a bug that made the material appear not correct but it doesn't seem to come from any new Energy Preservation Model.

I'm confused now, both render the exact same result. If the glass material in my scene just was a bug in an earlier V-Ray version how can I see the new Energy Preservation in effect and compare the difference? Do I need to enable it somewhere?

[JonasNöll]

Sorry for the confusion, I think it's cleared up now. Had to recreate the shaders for a noticable difference between 5 and 6. The difference in the refraction seemed to come from another issue, NOT the new energy conservation model. Here you can see the difference between V-Ray 5 and the new energy conservation model in V-Ray 6.