Pulling my hair out trying to isolate shadows from an object on a surface

[tricky]

I have a scene of a table top with a magazine that has the pages turning. The magazine was a bit of an afterthought, and is being rendered out seperately (without GI) with the idea of comping it onto the table in AE. Problem is, I cannot figure the way to render either the magazine and shadows together in one pass, or just the shadows in one pass (to be comped beneath the isolated magazine in post).

I am tying myself in knots here!

Matte/shadow materials, matte objects, alpha contribution, shadow brightness......

Is there a simple guide anywhere? Please bear in mind that it is a Friday

[Morbid Angel]

two ways you can do this, you will have to render twice for the first method. Make the magazine invisible to camera, so you only get shadow render it, then render the magazine with everything else hidden from camera. Second method is to have vray matte in object properties of the table to be set to -1 in alpha contribution, that will render the magazine with shadow of it on the table.

[tricky]

two ways you can do this, you will have to render twice for the first method. Make the magazine invisible to camera, so you only get shadow render it, then render the magazine with everything else hidden from camera.

D'oh! Told you it was a Friday! My brain tends to shut down on a thursday evening!!! lol

Thanks mate!