000000003333
000000000000
000000000000
000000000000
000000000000
000000000000
000000000000
000000000000
404040404040
404040404040
400400040000
400000400000
400000400000
004040004000
400040400000

76543210

0       -       Soild collidable (most walls)
1       -       Transparent single sided (windows)
2       -       Double sided collidable (not common)
3       -       Transparent Double sided (fences)
4       -       Animated non transparent (monitors)
5       -       Animated transparent 1 sided (audience)
7       -       Animated 2 sided trans. collidable (fire)
9       -       Transp. non collidable 1 side (city gates)
B       -       Non coll. dbl sided transp. (drive thru arch)


6 8 and A are highly unlikely and have never been used
F doesn't work (trans. dbl. anim. non coll.)
D may be possible for animated city gates, but hasn't been tested
