Alpha with transmission

[Dchimenti]

It's my understanding that, when using a high number in transmission (to simulate glass), one can see translucency represented in the alpha channel. And to achieve this, you have to assign "Arnold properties" to the object and make sure "opaque" is checked under General Properties.

This is not working for me.  The alpha is always solid white and does not show any translucency. What Am I missing? Has something changed?

I guess I have to mention that I'm using Gamma as my color manager.  I've had this particular detail screw me up in the past.

I've attached the simple project I'm working with.

[MartinBeh]

Not sure this helps but looking at https://help.autodesk.com/view/ARNOL/ENU/?guid=arnold_user_guide_ac_transmission_ac_transmission_opa... I found this comment:

Transmission and Alpha

If you want to see transmission in the alpha channel, enable transmit_aovs (under transmission of standard_surface. And if you're using a skydome_light, set its transmission to 0.

Actually not sure how this translates to the shaders used in 3ds Max but maybe it is a step in the right direction..? 

[Dchimenti]

Getting close. I'm getting transparency but it doesn't properly represent reflection or highlights.

I'm using Arnold lights

I also can't alter saturation of the transmission color without dramatically altering the alpha transparency.