I'm trying to cast a shadow in AE with a Zaxwerks element. I see where there is a light feature in Zax, but it doesn't cast a shadow on a layer below. I understand how to cast a layer in AE with AE 3D layers, but it doesn't seem to work with Zax.
Invigorator lights, with shadows enabled, allow shadows to be cast from one Invigorator object to another, so long as they're in the same scene. As you've discovered, those shadows do not extend to other AE layers.
As you know, AE lights can create shadows for 3d layers, if those the lights and layers are shadow-enabled.
In your situation, you could turn the Invigorator layer into a 3d layer and enable cast and receive shadows. You would then would then be able to generate the shadows you want. However, you have to be careful to keep the Invig layer oriented toward the camera at the correct distance, or the 3d illusion will be broken.
You know...this approach doesn't neccessarily work if you're doing a camera move with AE 3D layers + lights. Because you're continuously adjusting the INV layer to correspond with the camera's position (to not break the 3D illusion) the INV layer's (as an AE 3D layer) position gets disoriented with the other AE 3D layers and begins to throw odd shadows that wouldn't be expected from the AE Lights.