yes, sorry. actually i've fixed the alpha problem but i'm still having some trouble with compositing which i haven't done much of.. im working in after effects and the windows are only semi transparent above the horizon.. i'm using a dome light with a hdri and an environment map, which doesn't render obviously but for some reason i'm still getting some thing above the horizon.. also theres no reflections in the windows, do i need to do a separate reflection pass ? thanks for your help