Assuming "p1" is your plane then the world position of the top left
var tl:Vector3D = new Vector3D( -p1.width*0.5, 0, -p1.height*0.5); //top left var vtxPos:Vector3D = p1.sceneTransform.transformVector(tl); best way to check is to add a sphere to to the scene at that "vtxPos" position.
