Another option you can use is placing a 2D layer (a null works well) in between the 3D layers. This will effectively put the 3D layers in separate (but simultaneously visible!) universes =)
This can have strange results if you’re using lights.
In the future you should just line up your layers by the numbers in 3D space, the floor should be at the bottom of the wall.
A good way to line 3D layers up is by changing their anchor points to something like [0,0,0], then you know that the lower edge is thisLayer.height units away on the Y-axis in layer space.
So, for example create 3 800×600 solids, make their anchor points [0,0,0]. Parent two of these solids to the other solid. Notice that the positions of these children solids will be [0,0,0], if you change the position of one of them to [800,0,0] it will move to the very right edge of the parent solid. Change the other’s position to [0,600,0] and it will move to the bottom edge of the parent solid.
Darby Edelen
DVD Menu Artist
Left Coast Digital
Aptos, CA