Some three dimensional automata, namely 
automata using von
Neumann neighborhoods, are accessible to CAM
boards, given a
willingness to work with them plane by plane. Since four planes
altogether can be used, plane 0 could be regarded as sandwiched between
planes 2 and 3, to create a plane each of whose cells has a complete
three dimensional neighborhood of unit radius. Rather than having plane
0 evolve, the new generation could be recorded in plane 1 instead,
freeing the CAM
board to shift layers internally.