def vertices_vector_to_matrix(vertices):
    """vertices_vector_to_matrix(vertices) -> List[List[float]]
    PyPRT outputs the GeneratedModel vertex coordinates as a list. The list 
    contains the x, y, z coordinates of all the vertices. This function converts the 
    vertex list into a list of N vertex coordinates lists (with N, the number 
    of geometry vertices).

    Parameters:
        vertices: List[float]

    Returns:
        List[List[float]]

    Example:
        ``[[-10.0, 0.0, 10.0], [-10.0, 0.0, 0.0], [10.0, 0.0, 0.0], [10.0, 0.0, 10.0]] 
        = vertices_vector_to_matrix([-10.0, 0.0, 10.0, -10.0, 0.0, 0.0, 10.0, 0.0, 0.0, 
        10.0, 0.0, 10.0])``
    """
    vertices_as_matrix = []
    for count in range(0, int(len(vertices)/3)):
        vector_per_pt = [vertices[count*3],
                         vertices[count*3+1], vertices[count*3+2]]
        vertices_as_matrix.append(vector_per_pt)
    return vertices_as_matrix