polyline p 0 0 0 10 0 0 10 0 10 5 0 10 5 0 5 0 0 5 0 0 0
mkplane f p
prism b1 f 0 5 0
box b2 0 0 5 5 5 5
box b3 0 5 0 10 5 10

# make the shapes connected
makeconnected c b3 b1 b2

checkshape c
checknbshapes c -vertex 18 -edge 31 -wire 17 -face 17 -shell 3 -solid 3 -t
checkprops c -s 900 -v 1000

savehistory h

modified m3 h b3
checknbshapes m3 -face 7 -t

# make the shape periodic
cmakeperiodic cp -x 10 -y 10 -z 10
checknbshapes cp -vertex 26 -edge 42 -wire 20 -face 20 -shell 3 -solid 3 -t

savehistory h

modified m1 h b1
checknbshapes m1 -face 10 -t

modified m2 h b2
checknbshapes m2 -ref [nbshapes b2] -t

modified m3 h b3
checknbshapes m3 -face 8 -t


# check material associations
explode b3 f

# the face b3_3 is REVERSED
# materials on negative side should be only b3
# materials on positive side should be b1 and b2

modified mf h b3_3

compound pos 
compound neg

foreach f [explode mf f] {
  if {![regexp "No materials on this side" [cmaterialson p + $f]]} {
    add p pos
  }
  if {![regexp "No materials on this side" [cmaterialson n - $f]]} {
    add n neg
  }
}

# check that neg contains b3 only
checkprops neg -equal b3 -skip

# check that pos contains both 
compound b1 b2 comp
checkprops pos -equal comp -skip