VRay-LPE - Coat broken in 72002

[Dariusz_Makowski_Dadal]

Hello

So I’m having a bit of an issue…
See Pics:
C.*

C<R’mcoat’>L

C<R’mcoat’>.+L

C.*-(C<R’mcoat’>L)-(C<R’mcoat’>.+L)

Even stuff like (C.*L)-(C<R’mcoat’>*L) break as well.

We are clearly missing this specularreflection, which “coat” for some reason steals.

Can this be looked at/fixed?

Regards
Dariusz

[Dariusz_Makowski_Dadal]

PS 1
C<R’mcoat’>*L

I don’t understand why this LPE production, clear-coat only, cause specular to be subtracted from C.*

PS2 shader settings

[Dariusz_Makowski_Dadal]

P2
Also forgot to Mention, GPU CUDA and RTX render it CORRECTLY!!! Its only broken in CPU!!!
Cuda/RTX LPE >

Please fix this Bug, this is stopping our studio work with LPE’s…

[hermit.crab]

Try this on the CPU:
C.*-(C.‘mcoat’.*)

EDIT:
(C.*)-(C<‘mcoat’>.*L) - this also works. I guess for the CPU, there’s also a Diffuse Transmission (maybe because the coat is a layer on top of the shader?). Will investigate this.

EDIT2: Typo.

[Dariusz_Makowski_Dadal]

Hey @hermit.crab
Thanks for jumping on this
C.*-(C.‘mcoat’.*) appear to work! Thanks!!

Also:
(C.*)-(C<‘mcoat’>*L)
Appear to have reflection from other objects, but not from Dome… sooo kinda works?

[hermit.crab]

Corrected. There was a missing dot before the *L (without it, the ray is captured as directly ending in the light).
(C.*)-(C<‘mcoat’>.*L)

[Dariusz_Makowski_Dadal]

Thank you! @hermit.crab
Testing more…
Finding more… issues?

No coat>
(C.*)-(C<‘mcoat’>.*L)

COAT>
C<‘mcoat’>.*L

​
Left sphere Shader >

Why am I seeing Red COAT data inside NO_COAT render and the COAT render is missing red tint?

Seems like this is also… “broken” ?

Regards
Dariusz​
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[hermit.crab]

This is not an issue with the LPEs - it’s how the Coat layer works. Quoting from the docs:
Coat Color – Determines the coat layer’s color. The Coat Color tints all layers - reflection, sheen, diffuse, and refraction. Note that the coat specular highlights are not affected and are always white.

In other words, the LPE result you’re seeing is the tinted reflection below the coat, which is correct.

[Dariusz_Makowski_Dadal]

Hey

Hmmm that kinda sounds correct… I just expected it to be in mcoat pass mhmhmhmmmm, this is more like transmittance/refraction color of coat and not color coat then… ?
So if I wanted to make coat… blue, how would I do that?
For example, I’d like the coat to reflect pink, but not affect layer below…hmmm ?

Regards
Dariusz

[hermit.crab]

@Dariusz_Makowski_Dadal

Hey

Hmmm that kinda sounds correct… I just expected it to be in mcoat pass mhmhmhmmmm, this is more like transmittance/refraction color of coat and not color coat then… ?
So if I wanted to make coat… blue, how would I do that?
For example, I’d like the coat to reflect pink, but not affect layer below…hmmm ?

It’s more like a Color tint. As mentioned in the documentation, the highlights are always white. To get what you want, you need to do it the old way - using VRayBlendMtl and adding a LPE label on the main/coat mtl. Attaching a sample scene.
LPE_workaround.7z (11.1 KB)