Need Help with Hanging Gardens Rule

[jdroscha@...]

Designers,

The Roundhouse Gamers have been testing a piecepack 
ruleset called Hanging Gardens, and it's well oiled all but one 
sticking spot.  I'm looking for suggestions to knock this last bit of 
rust off.

I'll post full rules later (after they're written up formally) but here's 
the basics:  dump a whole piecepack on the table, take turns 
placing any two pieces, game ends when all pieces are played, 
then players count their scores.  The gardens are built from 
terraces (face down tiles, 2x2 spaces showing) and platforms 
(face up tiles), first with terraces flat on the table, then two 
platforms topped with a terrace to go "up" a level.  There's no 
fixed board; players stack levels as they desire.  Plant beds are 
represented by coins (suit/color side up), one per space.  Pawns 
stand for gazebos/cupolas from which the gardens are viewed 
(one per player).

The trouble takes place during scoring.  As part of scoring, you 
need to be able to determine with certainty which plant beds can 
be seen from a particular gazebo, given intervening obstructing 
levels (plateaus).  How do we construct a clean, 
easy-to-apply-and-remember rule for:
1)  Determining if a plateau is obstructing your view, regarding 
line of site in the X and Y plane.  That is, how do you define the 
line of site from overhead (bird's eye view).
2)  Determining if a plateau is obstructing your view, regarding 
line of site in the Z axis.  That is, how do you define the line of 
site as seen from the side of the board.

Some suggestions that have been put forth:
1)  string
2)  eyeball it (put your eye next to the pawn)
3)  have players vote
4)  [courtesy Dave Boyle] for Z axis visibility [assuming gazebo 
viewing height is 1 level greater than the height of the plateau the 
gazebo sits on]... the minimum distance a bed needs to be from 
the gazebo is = (height difference between gazebo and bed * 
distance from gazebo to plateau) / height difference between 
gazebo and plateau

The merits of suggestions #1 and #2 above are that they are 
simple and take care of all 3 axes at once, but the trouble is that 
they are imprecise (a slight nudge of tiles might change results).  
Suggestion #3 seems interesting, but with some groups of 
players it would never fly... such players would never vote in favor 
of other players.  Suggestion #4 seems to work for determining 
obstruction in the Z axis (and is based on the actual geometry of 
the situation), and is fairly easy to implement once you get used 
to it, but it is difficult to remember and some players would be 
put off by the formula; also, it does nothing to solve the problem 
in the X-Y plane.

So, is this enough information to obtain a few suggestions?  Let 
me know if you need clarification on anything.  I realize it can 
sometimes be difficult to grasp the essence of a game without at 
least seeing it played, but hopefully you can intuit the essentials.

Thanks,
James