// Set the size and position of the triangle provided to be that of the triangle index
 // specified.
 // This is called frequently so error checking has deliberately
 // not been included.
 public void GetTriangle(ref int index, ref Triangle triangle)
 {
     triangle.Resize(Vertices[Indices[index].A], Vertices[Indices[index].B],
         Vertices[Indices[index].C]);
 }