     fi = PI * @visualAngle()
     gd = @universe.geoData
     t1 = @angle - fi
-    t1 = @universe.tp sin(t1), cos(t1)
-    s1 = gd[ t1 + 3 ]
+    t1 = @universe.tp sin(t1), cos(t1), null, true
+    q1 = gd[ t1 + 3 ]
     t2 = @angle + fi
-    t2 = @universe.tp sin(t2), cos(t2)
-    s2 = gd[ t2 + 3 ]
+    t2 = @universe.tp sin(t2), cos(t2), null, true
+    q2 = gd[ t2 + 3 ]
     m.push t1
     m.push t2
-    m.push if s1 > s2 then s1 - s2 else 0
+    m.push if q1 > q2 then 4 - q1 else 0  # an adjustment factor to make it easier to compare quadrants
     m
   clean: ->
     for k, v of @others

          @geoData[ offset ]     = distance
          @geoData[ offset + 1 ] = sine
          @geoData[ offset + 2 ] = cosine
          @geoData[ offset + 3 ] = segment
          offset
      # produces a vector in the TrigPair direction with the given magnitude
      vector: ( offset, magnitude ) =>

      @topic.topicColor  = @outline
      @topic.inheritMark = false
      @draw()
  # highlight an organism by coloring its belly
  highlight: ( x, y, color, inherit ) ->
    for t in @thingsAt( x, y ) when t instanceof Organism
