UVGenerator for BufferGeometries

I have been using this style of code to generate UV coordinates for an ExtrudeGeometry

generateTopUV: function ( geometry, indexA, indexB, indexC ) {

	var vertices = geometry.vertices;

	var a = vertices[ indexA ];
	var b = vertices[ indexB ];
	var c = vertices[ indexC ];

	return [
		new THREE.Vector2( a.x * DESIGNER.scale, a.y * DESIGNER.scale),
		new THREE.Vector2( b.x * DESIGNER.scale, b.y * DESIGNER.scale),
		new THREE.Vector2( c.x * DESIGNER.scale, c.y * DESIGNER.scale)


The geometry has now switched to using Buffers and so this no longer works. When called the attributes list is empty so how do I get at a vertex list or is there a different technique?

Switched to three.js rather than three.min.js and it is obvious then!
Sorry to bother anyone.

Along the way I had to change the path code as this has changed to curves from actions. But again easy fix with the non-minimised library.