You can also cast your plane as mesh, create a nex ISegmentMaterial and add it as an outline :
var yourSegmentMaterial:WireFrameMaterial = new WireFrameMaterial
(yourColor,{alpha, widthOfSegment});
Mesh(plane).outline = yourSegmentMaterial ;/// don't remember why but
I had to cast it like that :yourSegmentMaterial as ISegmentMaterial
