fixed jitter in tri face highlighter

js/models/BasePlane.js

@@ -165,6 +165,7 @@ OctaBasePlane = BasePlane.extend({
     },
 
     calcHighlighterPosition: function(face, position){
+        position.z = 0;
         var index = globals.lattice.getIndexForPosition(position);
         if (index.z%2 != 0) index.x -= 1;
         index.z = this.get("zIndex") - 1;//pretend we're on the top of the cell underneath the baseplane