Hello

I'm wondering if the "dual LPE" syntax described in the OSL docs is supported in Karma? (I wasn't able to get it to work)

OSL Light Path Expressions [github.com]

Good, you got your alpha channel as a separate AOV, but what if you want to put it in the actual alpha channel of an RGBA AOV? You can do that by appending your expression to the standard rgb expression for an AOV. Look at this example:

Output ("beauty.tif", "rgba", "C[SGs]*D*<Ts>*L !C<Ts>*B")

No, it's not possible with karma (custom alpha has to be its own AOV)

Okay, that's what I suspected - thanks for confirming.