How to get a separate Reflection Pass from a Shadow Catcher

[RobH22]

How to get a separate Reflection Pass from a Shadow Catcher:

I've spent a week on this and have read 100s of posts, literally. I think I've so confused myself that I now can't see what is probably right in front of me.

I have a background image of a highly glossy beautiful wood table. I need put put a 3d object on that table, catch the shadow and catch the reflection. I need the shadow and reflection on separate layers in Photoshop so my client can turn them on and off at will. Easy enough right? Well not so much.

I can easily create the shadow layer. What I can't figure out is how to get the reflection as a clean pass all its own. In a composite beauty render it looks great, but with Render Elements, I just don't get the reflection of the 3d object in the shadow catcher.

For Render Elements I have: VRaySpecular/ VRayLighting/ VRay GlobalIllumination/ VRayReflection/ . I save them as EXR and with GlobalIllum on the bottom, I layer the others with 'Linear Dodge (add)'

In the RGBA composite pass I do have a great reflection. But I can't figure out how to generate a "seperate" reflection of the object on the shadow catcher surface below.

[fixeighted]

Quite simple: just enable 'matte for refl/refr' as in the attached

Actually, something seems to have changed in the version I'm using, (6.10.0 so having that box ticked doesn't do anything.
Rather, if you have the 'affect alpha' checked then that will suffice.

[RobH22]

fixeighted Thanks for the fast assistance. Yea, I've been trying turning off the 'Matte for refl/refr' under 'Matte properities' and too have found it does nothing. Maybe it's a bug. I'm using 6.20.02.

Turning (leaving it on as it's ON by default) on 'affect alpha' is not helping either. This is very frustrating. Hmmm....

If you felt like looking at it, here is my Max file and EXR layered file from Photoshop. https://drive.google.com/file/d/1Pzd...usp=drive_link

BTW, your work on Behance is Gorgeous...!

Edit: Can you send me the file you used above, if you saved it. If not, don't waste time redoing it. But if you have it, I might reverse engineer it.

[fixeighted]

On re-reading your initial post, maybe I misunderstood.
I think you were expecting the reflection of the object to be included in the reflection element, which isn't possible afaik....maybe using LPE, though I know nothing of that I'm afraid.

You do have options to get the required result though. So if you wanted 'only' the reflection of the object, then a workaround is a separate render with that object made invisible to camera but
of course still visible to reflections etc.
If you wanted a perfect white matte of that then just make the reflective surface non fresnel.

[nikoleta.garkova]

Hi RobH22,

There's no simple way to get information in the reflection pass yet, I'm afraid. It has always been like that - but over time, we had some requests to improve the behavior.
You can check the following forum topic on the matter, with suggestions for workarounds - meanwhile, we can bump our internal ticket (VMAX-10730) with another request.

[RobH22]

Hi Nikoleta, thanks for clearing that up. At least I know I'm not crazy. I spent more than a week trying to figure it out. It just seemed like it should be a simple thing to do. I'll look at the 'topic' you referenced for me. Thanks again...