Environment Reflection - Render Element

[Morne]

Hi Guys

Would be awesome if we can get a render element, specific for environment reflections.

Currently we use the free 3rd party Rendermask script for this, but there's usually some kind of issue with each new vray version.

Furthermore I think its a feature that should just come standard with the render engine.

USE CASE: typically to replace skies in glass reflections, in post

[^Lele^]

It's quite the perfect task for LPEs.

I think the expression is like so

C<R[GS]>*B

, but feel free to experiment.
There are three sources of documentation and examples on LPEs:
The basic Manual page, the Introduction to LPEs and the Advanced guide to LPEs.
You can also try out the LPE Builder (which also makes maxscript/MEL code for you so it's easy to add the REs)

[Morne]

Cool, thanks Lele
I'll check it out!

Is this specific to VRay 5, or I can set it up in Next also?

[^Lele^]

V5 exclusively.

[garipodelu]

It's quite the perfect task for LPEs.

I think the expression is like so

C<R[GS]>*B

, but feel free to experiment.
There are three sources of documentation and examples on LPEs:
The basic Manual page, the Introduction to LPEs and the Advanced guide to LPEs.
You can also try out the LPE Builder (which also makes maxscript/MEL code for you so it's easy to add the REs)

Hello Lele, I just stumbled upon this post and was wondering if there is a way to generate a B&W mask for the output so for example the environment reflection will be white and the rest of the image black.
Sorry if this is a stupid question but I'm struggling a bit on how to properly use this. I made a simple test scene, a box with a couple of windows that reflect the clouds from the sky (environment) and some pieces of geometry that also reflect in the glass.
Using your expression I get a image that is black and only has the environment reflection visible. If I compose this pass over the RGB (subtract - blending mode) I eliminate only the environment reflection (the reflection from other objects is still there as intended).
How can I replace the sky without a mask?
Thanks in advance.

[gagui]

Hello.

I'm trying to make a LPE where only refracted rays are visible and nor reflected nor specular rays are present.
The problem is my scene has two glassy materials one over the other. The refraction RE shows speculars of the first glass through the second glass and I need a refractions only RE for my comp.

Is this possible with LPE?

[gagui]

Well, I think I found a winner LPE: "(C<T[GS]>*<RD>L)-(C<RD>L)"

[gagui]

Would be good to have an offical place to recolect all this expressions with examples.

[gagui]

Hello.

Reviewing my last 3 posts I realize that this is not the best place to have them.
f any moderator read this please delete my last 3 posts and I will make a new thread with them in the general category.