Let’s say I render a tree with tree leaves but want to comp in a photo behind it post production. If I use render elements and Vrayalpha, the opacity map is not respected in the output. Instead of creating an alpha with defined leave structures, the whole geometry is included instead.
Does anyone know how to get the opacity map to be included in the Alpha as well?
Anyone have any answers for this?
Are you using the Opacity channel or the refract slot? Either one works for me (as long as affect alpha is checked for refraction) although I do get slightly different results.
I always use Opacity - but I never ever get textures with alpha (ie. a tree leaf) to show up in Vrayalpha render elements.
Works fine for me - just tried that.
Best regards,
Vlado
I probably should add that this is on Vrayproxies - not sure if thatll make a difference.
Got it to work - thanks! 
What was the problem?
Well ok lol - I was using vraymtlid and objid - both show up as solids. I chose the background picture and made it alpha contribution -1 and now it works fine with vrayalpha as a render element.
However, I’d still like to be able to use ObjID or MtlID and have it include the opacity maps.