hmm.. this si such an old mod, and really needs a lot of updating...
something changed with the stac node directions in an update, wayyy bac...
the Z coord needs to be flipped... you could do that
`    node_stack_top = 0.0, 0, -0.01, 0, 0, -1, 0` to
`    node_stack_top = 0.0, 0, -0.01, 0, 0,  1, 0`