I already did that, the problem is that it does not come with transparent background, it comes with a black background instead. The only way I can see this working somewhat is if I copy the hourglass' glass body, flatten the copy and then make it provide alpha from the glass' back, so that the specular can be seen while the bg is transparent.
I think you'll need to do render passes, such as a specular pass that you can layer on top of your diffuse pass, etc.
In the alpha channel I only see the hourglass' shape as white but the specular is in no way displayed as white in the alpha mode. When I've made a render pass export, this is what I ended up with. As you can see, there is no transparency in the specular render's background.
sometimes the transparency may only be visible via the alpha channel in this case...have you checked?
Yeah but how would I composite the specular? (what I meant by this is - I have tried all possible operations when overlaying the two files, I only end up with a faint rectangular background, which still does not keep transparency of the background to full). Does this mean I'd have to make a specular with something else? Also, this is my workaround for what I needed (see attachment). I've copied the glass, flattened it and added a yellowish color to it and set its transparency to act as alpha behind the glass. It's pretty close to what I wanted so I guess this will do for what I need it (a graphic in a power point presentation).
As far as I know specular doesn't show in the pass. It's supposed to be composited with an add operation.