/// <summary>
/// Parse a face.
/// </summary>
void ParseFace()
{
SkipWhitespace ();
var face = new ObjFace ();
var raw = ReadVertexGroupString (ReadLine ());
for (var i = 0; i < raw.Length; i++) {
var vertex = ExtractFaceVertex (raw [i]);
var vi = vertex.VertexIndex;
var ti = vertex.TextureIndex;
var ni = vertex.NormalIndex;
this.Log ("Read face vertex (V:{0}; T:{1}; N:{2})", vi, ti, ni);
face.Vertices.Add (vertex);
}
if (result.Groups.All (e => e.Name != currentGroup)) {
result.Groups.Add (new ObjFaceGroup (currentGroup));
this.Log ("Added face group {0}", currentGroup);
}
var g = result.Groups.First (e => e.Name == currentGroup);
g.Faces.Add (face);
}