point2point = function(p1, p2) {
        var vx = p1.x + p1.parent.x - p2.x - p2.parent.x;
        var vy = p1.y + p1.parent.y - p2.y - p2.parent.y;
        var vz = p1.z + p1.parent.z - p2.z - p2.parent.z;
        return (vx * vx + vy * vy + vz * vz);
    }
@scope enchant.gl.collision.BS.prototype