Re: Cube in Boris, more

Using the Boris Cube inside AE requires that you have the media files you want to have on the individual faces actually included in your timeline. Turn off the eyeballs for them so they are invisible. In the Boris Cube controls, there is a popup for each of the six faces that will reveal al of the layers in your composition. (Rename the layers so they mean something, like, "Big Oak Trees" instead of "layer one.")
You can adjust the transparency of the front layer but if you want to apply other effects or controls to the individual layers BEFORE they they are applied to the Cube's faces, you must precompose the layer. Typical of most compound effects that reference other layers, Cube sees the source footage at the beginning of any rendering pipeline. Precomp the back layer and set Scale to -100% horizontal, 100% vertical to reverse it. You can apply a nice light swipe to the sides to make them look like edges of glass. Add a coolness factor by applying a transparent copy of your back and front faces to the edges to simulate internal reflections as the camera or cube moves. Use the Cube Depth to vary the thickness of your glass slab. And use displacement to get the edges to touch.

david