alpha channel problem

[Komposer]

hi,
there is a strange thing with the alpha channel, when I render with reflections.
When I set the advanced option "Affect Channels" to Color only - everything is fine.
When I set the advanced option "Affect Channels" to All channels - I get the strange result.
This can´t be normaly - or!?
Any idea? - Thanks

(Win7, Maya 2015, Vray3.15) - in the official 3.0 - the same!!

[ivaylo.ivanov]

All channels will affect also the alpha.

[Algehov]

It looks like its working. Its the background you see reflected, in the alpha channel.

[Komposer]

thanks for Your help!
It´s correct what You say - it affects all channels - didn´t notice what I red
But for me, that make no sense, because of my normaly postprozess...
I need a normal alpha-channel for composeting...
But I wish, that the reflected objects are includet in the material ID´s!
hmmm....

[ivaylo.ivanov]

There is an idea to make this option per render element, but it's still in the "todo" list.

[Algehov]

I guess as a workaround you could add an extraTex element with just pure white in it. And you could use that as your new alpha?

[Komposer]

todo sounds great!
..and yes, the pure white solution is a way, but I´ve over 30 shots and more than 15 render layers..
So I decide to go the "color only way"
Thanks for response.

[Yves Adam]

There is an idea to make this option per render element, but it's still in the "todo" list.

How far down the list is this ? and it is on the list for 3ds Max as well ?

I could REALLY use this in our workflow and I do mean REALLY.
For Archviz we render with a lot of passes but what I am missing is the shadow that hit's the glass before passing through it.
Another pass we need is 3d reflection (so a mask of only actual geometry reflection) this works when I set it to affect all channels (the reflection)
but I for all other elements I DON'T want it ... (so I have it set to color only, but then the 3d reflection is gray where it doesn't reflect 3d geometry instead of black)

Could this be something that could be moved to one of the next nightly builds ?