VRay 3.6/Maya - Correct way to get alphas when using the dome light (with a transparent object)?

[KiloWattson]

Hey guys - I'm sure this is simple and I've searched but haven't *quite* found the solution.

I'm using the Dome Light and an HDRI map to light a clear acrylic plastic trophy.

Looks great until I realize I can't get an alpha channel.

If I go to the dome light and uncheck alpha it gets me an alpha around the object, but not for any of it's transparency.

If I go to the material and check "color + alpha" under the reflection options, it gets me closer. But it doens't feel quite right.

I'm fairly novice when it comes to VRay so I'm sure i'm just overlooking it. I just figure when I make my object transparent it will automatically apply to the alpha. Not so apparently!

[francomanko]

set the dome light to invisible (under options)? Is that what you are after?

[KiloWattson]

Thanks for the reply, but nope. And I actually had that in an earlier draft of my message but apparently left it out, doh!

If I do that, it just basically turns off the dome light and still blocks/fills the whole alpha.

[francomanko]

you mentioned you changed reflection to color and alpha, did you change the refraction to all channels?